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Plant Crib ACAENA, TAXA WITH SPHERICAL HEADS For a full account of Acaena with spherical heads cultivated in the Britis...

Author: T. C. G. Rich & A. C. Jermy

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Plant Crib

ACAENA, TAXA WITH SPHERICAL HEADS For a full account of Acaena with spherical heads cultivated in the British Isles, see Yeo (1973). For colour photographs of A. ovalifolia, A. inermis and A. anserinifolia, see Yeo (1982). Five Acaena taxa with spherical heads are likely to be found naturalised. They may be distinguished as follows: A. ovalifolia Ruiz & Pav.: Leaves bright green, finely wrinkled, glossy (Fig. a). A. novae-zelandiae Kirk: Leaves bright green, glossy (Fig. b). A. anserinifolia (J. R. & G. Forst.) Druce (including A. pusilla (Bitter) Allan): Leaves heavily flushed with brown, matt (Fig. c). A. inermis Hook. f.: Leaves bluish-grey, flushed with brown, matt (Fig. d). A. anserinifolia × A. inermis: Leaves greyish olive-green, matt (Fig. e).

Leaves of Acaena (not to scale).

References Yeo, P. F. (1973) in Plants: wild and cultivated. BSBI conference Report no. 13. Appendix III. BSBI, London. Yeo, P. F. (1982). The Garden 107: 326-328. Author

P. F. Yeo, M arch 1988.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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ACONITUM, BLUE-FLOWERED TAXA Blue-flowered Aconitum taxa are widespread as garden-escapes and are most commonly recorded as 'A. anglicum' or 'A. napellus', but often incorrectly. The endemic native plant of shady riversides in SW England and S Wales is A. napellus L. subsp. napellus (A. anglicum Stapf), which has purplish-blue flowers in early summer (map in Scarce Plants). Although colonies of garden origin are sometimes the same, escapes are more often later flowering taxa with a different leaf-shape and deeper blue flowers. They are commonly A. napellus × A. variegatum L. (= A. × cammarum L.). The A. napellus parent is usually subsp. napellus, but A. napellus subsp. vulgare × A. variegatum has also occurred as an escape. Important characters in the identification of these plants are: a) The shape of the uppermost 'petal' (actually a petaloid sepal) which forms a hood-like structure, the 'helmet' (Figs. e-g). Note that the use of the helmet dimensions in the key refers simply to this hooded part, not to the whole 'petal'. b) The orientation of the posterior nectaries or honey-leaves, which form narrow petaloid structures, either extending vertically up into the rear of the helmet or else curving forwards to become horizontal (Figs. e-g). c) Pollen fertility, well formed pollen being more or less globose, inconspicuously furrowed and readily taking up acetocarmine stain. Presumed inviable grains remain ovoid, conspicuously furrowed, take up little or no stain, or are at least conspicuously small. Note, however, that these plants seem prone to fungal attack of the anthers, reducing the percentage of viable pollen, and also that they are self incompatible and so will not set seed if present as a single clone. The crowding of the leaves below the inflorescence, though used by some authors, seems to be a character of very little significance.

Major leaf divisions (a) A. variegatum, (b) A. × cammarum, (c) A. napellus subsp. napellus, (d) A. napellus subsp. vulgare.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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1 1

2 2

Inf lorescence a straight, stif f ly erect, many -f lowered spike; leav es much subdiv ided, ultimate leaf -lobes usually less than 6mm wide; f lowering commencing late spring or summer 2 Inf lorescence f lexuose to noticeably 'zigzagged' at the nodes, with 3-10 f lowers; leav es leathery , not alway s deeply subdiv ided, ultimate leaf -lobes more than 6mm across; f lowering commencing early autumn (escape, Kirkcudbrightshire and probably elsewhere) A. japonicum Thunb. Helmet hemispherical, i.e. about as broad as high (Fig. g); posterior nectaries curv ing f orward horizontally; pedicels densely pubescent; flowers usually dark blue; pollen fertility abov e 80% in healthy anthers 3 Helmet usually 1.5-2 times as tall as broad (Figs. e, f ); posterior nectaries v ertical or curv ing f orward horizontally; pedicels pubescent or glabrous; f lowers dark blue or blue/white bi-coloured; pollen f ertility likely to be low 4

3

Ultimate leaf -lobes linear to v ery narrowly linear-lanceolate, tips obtuse to acute but not extending into a fine point (Fig. d); inf lorescence a compact spike, with pedicels short and appressed to inf lorescence axis (at most a rare escape, but all records need conf irmation)

3

Ultimate leaf -lobes narrow, tapering f rom base into a f inely -pointed apex (Fig. c); inf lorescence a compact spike or rather lax (native and rare escape) A. napellus L. subsp. napellus

4

Posterior nectaries v ertical (Fig. e); pedicels (alway s?) glabrous; pollen f ertility abov e 80% (all records require confirmation)

4

Posterior nectaries ascending, tips curv ing f orward horizontally (Fig. f ); pedicels minutely pubescent; pollen fertility below 20% (much the most f requent escape in N England and Scotland) A. × cammarum L.

A. napellus L. subsp. vulgare (DC.) Rouy & Foucaud (A. compactum Rchb.)

A. variegatum L.

References Gotz, E. (1967). Feddes Repertorium 76: 1-62. Seitz, W. (1969). Feddes Repertorium 80: 1-76. Author

A. J. Silverside, February 1988, revised 1998.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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AGRIMONIA EUPATORIA / A. PROCERA When well-developed, A. eupatoria L. and A. procera Wallr. may be separated using Stace’s New Flora, though the following notes may help. i) The hypanthium may lose its characteristic bell-shaped shape in forms of A. procera in which a single seed is formed instead of the normal two, making it appear obconical.

ii) Large, glandular, distinctly aromatic forms of A. eupatoria which can be mistaken for A. procera; this form has been noted in Durham. iii) The bristles may be reflexed to 90° in A. eupatoria, which is more than usually illustrated. iv) The petals are usually notched in A. procera and entire in A. eupatoria (V. Skalický, pers. comm. 1994). v) The stems and lower surface of the leaves have subsessile glands much more abundant than hairs in A. procera (Fig. a) and hairs much more abundant than subsessile glands in A. eupatoria (Fig. b).

a

b

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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ALCHEMILLA

1. Introduction, especially to A. mollis In terms of ‘biomass’, by far the commonest Alchemilla in most of Britain today is the robust garden plant Alchemilla mollis. This plant is usually what gardeners mean when they say ‘Alchemilla’, and it is essential to recognise it from the native species, because it is increasingly becoming naturalised in Britain. Although A. mollis is included in Stace’s New Flora, the treatment fails to make it sufficiently clear how different this alien species is from any other British Alchemilla. It belongs to the series Elatae, typically robust plants characterised by the relatively large yellowish flowers on which the four epicalyxsegments are as long and often as wide as the alternating sepals, so that the open flower has the appearance of an eight-pointed star. Learn to recognise A. mollis when it flowers in your garden, and satisfy yourself that you can see the difference in the individual flower (Fig. a). (The three other Elatae Alchemillas are in cultivation in Britain but they are much rarer than A. mollis and are not currently known in the wild. Details, including a key, can be found in Walters (1991).) Excluding A. mollis, there are only three Alchemilla species you are likely to see in lowland Britain. Learn to distinguish these: with practice, all you need is a single leaf! Records for all the rare and scarce plants are very sparse since the 1950s and detailed information, preferably with voucher specimens, is urgently needed.

2. Key to common lowland species (including A. mollis) 1 1

Epicaly x segments about as long as sepals (Fig. a); tall robust plants A. mollis (Buser) Rothm. Epicaly x segments distinctly shorter than sepals (Fig. b); often small plants 2

2

Nearly glabrous plants with some appressed hairs on petioles and the lowest stem internode

2

Plants with obv ious ± spreading hairs, at least on petioles and lower part of stem

3 3

Leav es practically glabrous abov e; flowers and pedicels ± glabrous Leav es hairy on both sides; backs of f lowers hairy

A. glabra Neygenf. 3

A. xanthochlora Rothm. A. filicaulis Buser

Epicalyx segments. (a) A. mollis (series Elatae) (b) native taxa.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Notes on the ‘lowland species’ All three common lowland species can also be found in upland areas. A. glabra is at first glance glabrous, but look carefully for the appressed hairs, especially on petioles. Be careful not to be misled by specimens infected with mildew: the stalked conidia (reproductive bodies) can look like spreading hairs! A. xanthochlora sometimes has a few hairs distally in the folds of the upper side of the leaf. A. filicaulis presents the most difficulty. The widespread lowland variant is subsp. vestita (Buser) M . E. Bradshaw; it has spreading hairs throughout all parts of the plant. In Britain subsp. filicaulis, with the upper part of the stem, inflorescence and pedicels glabrous, is an upland or mountain plant, often (in grazed pasture) very small (Bradshaw1963a). A. minima Walters, described from Ingleborough, is a genetically dwarf variant of A. filicaulis, best treated as A. filicaulis var. minima (see Bradshaw 1964; Walters 1949, 1970, 1986). 3. Upland and mountain Alchemillas Alchemilla alpina and related species In several mountain areas of Britain and Ireland, the true Linnaean Alchemilla alpina occurs, sometimes (as in western Lake District and many Scottish mountains) in local abundance. Note that this species is absent from the Welsh mountains. The plant most gardeners call A. alpina, the ‘Alpine Lady’s M antle’, is not the British (and Scandinavian) native, but a related, more vigorous and handsome species A. conjuncta Bab. (There is a third ‘alpina’ species not uncommonly grown, which is the Alpine A. plicatula Gand., but this seems not to have been recorded as a garden escape). Be sure you can distinguish true A. alpina from A. conjuncta: the silhouettes in Stace’s New Flora do not unfortunately show that all 5(-7) leaflets in A. alpina are separate to the base, whilst all 7(-9) A. conjuncta leaflets are obviously joined at the base. A. conjuncta, even in its long-established Glen Clova locality, is now considered to be originally introduced via gardens. It is now quite widely recorded in Britain, not always in mountain areas. ‘Vulgaris’ Alchemillas Upper Teesdale and Weardale, and to a lesser extent the Craven area, are the regions in Britain which have the greatest number of Alchemilla species. Stace’s New Flora includes all the rare and local species, but it is desirable to have a voucher specimen confirmed by a referee, especially if the record, if proved correct, is from a ‘new’ area. Here are some hints - and warnings! i) Be very careful to collect one or more summer basal leaves which belong to (and ideally are attached to) flowering stems. In Alchemilla-rich areas it is quite normal for several species to be growing mixed together. ii) The only ‘Vulgaris’ species with glabrous upper leaf surface and spreading hairs elsewhere is A. xanthochlora. Look critically at all Alchemillas with hairy upper leaf surfaces; these are the interesting ones. Note that, in well-grown A. filicaulis, there is nearly always a rich wine-red colour at the base of the plant. None of the other species normally shows this (particularly useful in distinguishing A. filicaulis from A. glaucescens). iii) In areas other than the ‘classical’ Alchemilla-rich ones, more and more interesting records for e.g. A. acutiloba, A. gracilis and A. tytthantha are turning up. This may be partly due to the paucity of sharp-eyed botanists, but suggests also that in ‘waste places’ some of these rare species are still spreading (see, for example, Dickson et al. 1993). iv) The species with appressed hairs, which (except for A. glabra) are exclusively mountain and upland plants in Britain, present a special difficulty. The best general advice is to look closely at the plants in Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib two respects, namely: are there any appressed hairs on the second and third stem internodes and/or on the upper leaf surface, and are the teeth acute and regular? Typical plants of A. wichurae and A. glomerulans are relatively easy to distinguish from A. glabra; but there are still problems with some British material, and it would be sensible to collect a voucher specimen of any plant that differs from A. glabra in the ways indicated.

4. Conservation problems Unless there is abundant material, make only one decent pressed specimen with at least one basal summer leaf and the corresponding flowering stem, and send it to a referee. The biggest problem for mountain Alchemillas is over-grazing by sheep: the human pressure pales into insignificance beside the destruction of whole herb-rich communities by excessive sheep-grazing! The best illustrations I know for British Alchemilla are the coloured plates in Garrard & Streeter (1983). The originals of these are water-colours by the late Ian Garrard: until I saw these I did not believe that any artist could so faithfully reproduce not only the shape, but also the texture and even the hairiness of the leaves. For the critical northern Alchemillas related to A. glabra, I recommend the coloured leafillustrations in M ossberg et al. 1992 (the text is in Swedish, but Latin names are given).

5. Alchemilla in the Yorkshire Dales Of the two main areas of Alchemilla diversity in Britain, those of Teesdale have been described by Bradshaw (1962, 1985) and those of the N England in general in Wigginton & Graham (1981: NB note in this that couplet 20 on their page 48 should read that there is no distinct incision between the lobes for A. glabra and that a distinct incision is present in A. wichurae). The following key is to the second main area of diversity in the Yorkshire Dales (for a full account see Roberts 1992). 2

1 1

Leav es and/or petioles with conspicuous dense spreading hairs Leav es and petioles hairless or hairs inconspicuous and ± appressed to surf ace

2 2 3

Upper-side of leaf ± hairless A. xanthochlora Rothm. Leaf ± hairy all over (rarely sparsely hairy on upper surface) 3 Plant compact, neat, deeply glaucous, densely sof tly silky -hairy , with ‘lambs-ear’ f eel; leav es neat, rounded; no wine-red colour at base of plant (locally v ery abundant on limey soils)

3

Plant dull blue-green to mid-green, not sof tly silky -hairy (perhaps coarsely hairy ); leav es usually reniform, not round; often richly wine-red at base of petioles and base of stem (various soils; much more widespread) (note 1)A. filicaulis Buser

4

A. glaucescens Wallr. subsp. vestita (Buser) M . E. Bradshaw 4

Leaf round; lobes rounded with teeth v ery f ine and ev en-sized; basal lobes ov erlapping; obv ious incision between lobes (sparse; typically on wet rocks by waterfalls and in short limestone turf, especially by tracks)A. wichurae (Buser)

Stefánsson 4

Not as above; teeth broader and vary ing in size

5

5 5

Upper leaf -surf ace ± hairless (v ery common) A. glabra Neyg. Upper leaf -surf ace with inconspicuous but usually abundant ± appressed hairs all ov er (very rare plant)A.

Buser

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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glomerulans

Plant Crib Note 1. The two other forms of A. filicaulis would key out here; both are rare. Both have sparser hairs on the upper surface of the leaf than A. filicaulis subsp. vestita. Both have been mentioned earlier under Section 2. References Bradshaw, M . E. (1962). The distribution and status of five species of the Alchemilla vulgaris L. aggregate in the Upper Teesdale. Journal of Ecology 50: 681-706. Bradshaw, M . E. (1963a). Studies in Alchemilla filicaulis Bus. sensu lato and A. minima Walters. Introduction, and I. M orphological variation in A. filicaulis sensu lato. Watsonia 5: 304-320. Bradshaw, M . E. (1963b). Studies in Alchemilla filicaulis Bus. sensu lato and A. minima Walters II. Cytology of A. filicaulis L., sensu lato. Watsonia 5: 321-326. Bradshaw, M . E. (1964). Studies in Alchemilla filicaulis Bus. sensu lato and A. minima Walters III. Alchemilla minima. Watsonia 6: 76-81. Bradshaw, M . E. (1985). Studies on the flora of Teesdale. Naturalist 110: 3-21. Bradshaw, M . E., Sell, P. D. & Walters, S. M . (1963). The nomenclature of Alchemilla minor auct. Brit. Watsonia 5: 259-261. Bradshaw, M . E. & Walters, S. M . (1961). A Russian Alchemilla in south Scotland. Watsonia 4: 281-282. Dickson, J. H., Hunter, R. & Walters, S. M . (1993). Alchemilla acutiloba Opiz new to Scotland. Botanical Journal of Scotland 46: 499-502. Garrard, I. & Streeter, D. (1983). The Wild Flowers of the British Isles pp. 84-85. M acmillan, London. M ossberg, B., et al. 1992. Den nordiska Floran. Wahlström & Widstrand, Stockholm. Roberts, F. J. (1992). Notes on Alchemilla and Viola in the Ingleborough area. Unpublished m/s for BSBI M eeting 1992. Swan, G. A. & Walters, S. M . (1988).Alchemilla gracilis Opiz, a new species to the British flora. Watsonia 17: 133-138. Walters, S. M . (1949). Alchemilla vulgaris L. in Britain. Watsonia 1: 6-18. Walters, S. M . (1952). Alchemilla subcrenata Buser in Britain. Watsonia 2: 277-278. Walters, S. M . (1970). Dwarf variants of Alchemilla L. Fragm. Flor. et Geobot. (Warsaw) 16: 91-98. Walters, S. M . (1986). Alchemilla: a challenge to biosystematists. Acta Univ. Ups. Symb. Ups. 27: 193-198. Walters, S. M . (1989). Alchemilla mollis (Buser) Rothm. and related species in gardens. BSBI News 51: 23-24. Walters, S. M . (1991). Alchemilla update. The Garden 116(2): 62-63. Walters, S. M . (1995). Alchemilla L. European Garden Flora 4: 399-404. Authors

Sections 1-4 S. M . Walters, February 1998, section 5 F. J. Roberts, February 1998.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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ALISMA A. lanceolatum differs from A. plantago-aquatica in a number of characters, of which the floral and fruiting are the most reliable. Leaf-shape is often distinct, but leaves of A. plantago-aquatica can approach those of A. lanceolatum in shape when young or when floating on the surface of the water (see illustrations), and it is unwise to record A. lanceolatum on the basis of leaf shape alone. There seems to be little consistent difference in flowering times. A. lanceolatum is under-recorded, at least in Ireland.

a

b

Carpels (a) A. plantago-aquatica, (b) A. lanceolatum.

A. plantago-aquatica L.: At least some leaves elliptical-ovate to ovate, rounded to subcordate at base (Figs. c-e); inner perianth-segments rounded; style arising about middle of carpel (Fig. a); anthers about twice as long as wide. A. lanceolatum With.: Leaves lanceolate, gradually narrowed at base (Figs. f, g); inner perianth-segments pointed; style arising above the middle of the carpel (Fig. b); anthers about as long as wide. The hybrid A. × rhicnocarpum Schotsman seem to be regularly reported but also seems to be confused with the variation in leaf shape of A. plantago-aquatica even on the same plant (compare Figs. c, d with Fig. f). Hybrids are often best assessed in the presence of both parents, and appear to be highly sterile with no or only 1-2 fruits developing in each flower. Some putative hybrids have a combination of cuneate and cordate/truncate leaves on the same plant. Do not record on leaf shape alone (Fig. H); please collect voucher material.

c

d

e

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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f

g

h

Leaves (c ) A. plantago-aquatica all from one plant, (d) A. plantago-aquatica, all from another plant, (e) A. plantago-aquatica, different plants, (f) A. lanceolatum, all one plant, (g) A. lanceolatum, different plants, (h) A. cf. × rhicnocarpum, all one plant.

Authors

M. J. Wigginton & G. G. Graham 1981, updated T. C. G. Rich & R. V. Lansdown, 1998.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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ALNUS 1. Alnus glutinosa × A. incana Hybrids between these two species have been twice recorded from wet woodlands in Ireland and also occur in Britain. M orphologically the hybrids are intermediate in most respects between the two species, though somewhat more similar to A. incana (L.) M oench than A. glutinosa (L.) Gaertn. The hybrids are difficult to identify conclusively as they overlap in nearly all morphological features with one or other parent. The only diagnostic character of the hybrid appears to be much higher gland density on the underside of its leaves (c. 6 per mm2): the parent species have a much lower density (c. 0-2 per mm2) on the under-surface of their leaves. Reference

Parnell, J. (1994). Watsonia 20: 67-70.

Author

J. Parnell, January 1998.

2. Alnus rubra Alnus rubra Bong. (see Stace’s New Flora 2nd ed. 1997) is occasionally planted and may be confused with A. incana. The leaves differ in shape and are rolled under at the edges (flat in A. incana), and the twigs are reddish and glabrous (hairy at ends of last years twigs in A. incana).

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ANTHYLLIS VULNERARIA A. vulneraria L. is taxonomically very complex, consisting of numerous inter-grading variants which are to some extent ecologically and geographically separated (Cullen 1986). Descriptions of the five subspecies are given with lists of Vice-counties from which they have been reported to date. Stewart (1987) gives illustrations of the subspecies. As a reminder: canescent = covered with dense, fine, greyish-white hairs; sericeous = with long silky hairs, usually appressed; hirsute = covered with long, rather stiff hairs. When collecting material, please note flower and calyx colours and include some mature basal rosette leaves which may have equal or unequal leaflets (Figs. a, b).

a

b

Leaflets of Anthyllis (a) Inequifoliate, (b) ± Equifoliate

a) subsp. vulneraria: Stems decumbent to ascending, sericeous or canescent-sericeous, rarely hirsute below; leaves evenly distributed along the stem; calyx usually with a red tip; corolla yellow or red, rarely orange, purplish or whitish. i) var. vulneraria: Corolla yellow; most leaves equifoliate; stems sericeous, rarely hirsute below, rarely branched in the upper part; branches, when present, shorter than the leaves which subtend them. Native; usually in open calcareous grassland in V.c. 1-4, 6-8, 12, 13, 15-17, 20, 22-24, 26, 29, 33, 50, 52, 57, 64, 66-68, 70, 83, 90, 95, 101, 104, 106, 111, H9, H14, H17, H18, H28, H40 and S. ii) var. langei Jalas: Corolla yellow to pink or red or purplish; most leaves equifoliate; stems canescent-sericeous, always branched above, the branches exceeding their subtending leaves. Native; sand-dunes and sea-cliffs in V.c. 1- 4, 9, 10, 14, 15, 27, 28, 35, 45, 46, 48-52, 59, 60, 67-70, H1, H3, H9, H16, H28, H38-40 and S. iii) var. coccinea L.: Corolla red; plants usually small, stem decumbent and very sparsely sericeous. Native; sea-cliffs in V.c. 1 and 45. b) subsp. polyphylla (Ser.) Nyman: Upright; stems hirsute below, sericeous above; leaves mostly equifoliate with 9-15 leaflets, evenly distributed along the stem; calyx usually without a red tip; corolla pale yellow. Introduced forage plant or sown on roadsides in V.c. 9, 22, 23, 29, 51, 85, 89, 95 and 96 (Akeroyd 1991). Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib The most similar subspecies in Britain is subsp. carpatica, which differs mainly in having inequifoliate stem leaves and a more swollen calyx with somewhat spreading hairs. The tall erect growth form of both is distinctive in the field. c) subsp. corbierei (C. E. Salmon & Travis) Cullen: Upright; stems hirsute over their whole length; leaves somewhat fleshy, concentrated in the lower part of the stem; calyx usually not red-tipped; corolla clear yellow. Native; cliffs in V.c. 1, 52, 109 and S and probably elsewhere. d) subsp. carpatica (Pant.) Nyman: Upright; stems up to 100 cm, sparsely sericeous; leaves usually concentrated towards the base of the stem, mostly inequifoliate; calyx red-tipped; corolla yellow or whitish. All British and Irish material is referable to var. pseudovulneraria (Sagorski) Cullen. Introduced forage and amenity seed mixture plant; disturbed habitats, especially newly sown road verges, in V.c. 9, 19, 22-24, 26, 27, 29, 33, 45, 57, 63, 69, 71, 73, 95, 106, 107 and H14. e) subsp. lapponica (Hyl.) Jalas: Decumbent to ascending; stems 10-40 cm, canescent-sericeous; most leaves inequifoliate; calyx rather hirsute, usually red-tipped; corolla yellow. Native; mountains and rocky ground near the sea in V.c. 68, 69, 82, 88, 90, 92, 101, 103, 104, 108, 110, 111, 112 and H28, and is apparently widespread in N and W Ireland. Plants that are intermediate between this and subsp. vulneraria occur in the lowlands and valleys of Scotland. References Akeroyd, J. R. (1991). Watsonia 18: 401-403. Cullen, J. (1986). Notes Royal Botanic Garden Edinburgh 43: 277-281. Stewart, O. M . (1987). BSBI News 47: 12-15. Author

J. R. Akeroyd, February 1988, updated 1998.

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AQUATICS WITH FINE, LINEAR LEAVES (ELEOGITON, JUNCUS, NAJAS, PILULARIA, POTAMOGETON, RUPPIA AND ZANNICHELLIA) Species of these genera can appear very similar in water, but are readily separated when flowering or fruiting (Figs. a-f). The following key may help with vegetative material: 1 1

Leav es with 2 obv ious hollow tubes, at least when mature (look at middle of leaf end-on with a ×20 lens)2 Leav es solid, lacking 2 hollow tubes 5

2 2

Ligule 5-15 mm long Potamogeton pectinatus / P. filiformis (see page 320) Ligule absent (NB: auricles may be present which can look like a ligule in pressed material) 3

3 3

Apex minutely toothed (×20 lens); roots at stem nodes absent Apex entire; roots often present at stem nodes

4 4

Hollow tubes with transv erse septae (may be inconspicuous); auricles present at top of sheath; untidy habit with clusters of leav es arising at interv als along the stem (note 1) Juncus bulbosus Septae absent; auricles absent; stem leaves not in specific clusters Eleogiton fluitans

5 5

Leav es spinulose-serrate (×20 lens) Leav es entire

6 6

Y oung leaves and shoot apices curled at apex like shepherds crook Y oung leaves straight

7

Some leav es in opposite pairs, at least abov e; plant of ten tuf ted, untidy in appearance

7

Leav es alternate

Ruppia 4

Najas flexilis 6 Pilularia globulifera 7 Zannichellia palustris Potamogeton

Note 1. Strictly speaking the aquatic state of J. bulbosus does not merit taxonomic recognition as it is simply a phenotype which develops under particular conditions. However it is useful to have a name for it, and "var. fluitans" is available as a convenient label.

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Plant Crib

a

b

c

d

e

f

Fruits (a) Eleogiton fluitans, (b) Juncus bulbosus, (c ) Najas flexilis, (d) Potamogeton, (e) Ruppia, (f) Zannichellia.

Authors

T. C. G. Rich & C. D. Preston, December 1997.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

ARENARIA SERPYLLIFOLIA Three subspecies of A. serpyllifolia L. are recognised in Britain and Ireland which form a series ranging from the slender subsp. leptoclados through subsp. serpyllifolia to the stout subsp. lloydii (subsp. macrocarpa). Subsp. leptoclados is scarce but widely distributed on open, sandy soils and on limestone walls and may be significantly over-recorded. Subsp. serpyllifolia is common. Subsp. lloydii is confined to the coast, and may not be distinct (cf. Stace’s New Flora). A re-evaluation of the taxa in this genus including cultivation experiments would be worthwhile. The best characters are seed size and capsule shape (Figs. a-c). The other characters help indicate the general look of the plant. The flower diameters and seed colours given in older accounts are not diagnostic. Subsp. leptoclados

Subsp. serpyllifolia

Subsp. lloydii

c. 0.4 × 0.4 mm

Reniform, c. 0.5 × 0.4 mm

Reniform, exceeding 0.6 × 0.4 mm

Capsule Straight-sided, less than 3 × 1.5 mm, possible to indent without fracture when pressed at maturity with fingernail (Fig a)

Distinctly swollen at base, exceeding 3 × 1.5-2 mm, not possible to indent without fracture at maturity (Fig. b)

Slightly swollen at base, exceeding 3 × 2 mm, not possible to indent without fracture at maturity (Fig. c)

Pedicel in fruit

Slender, upturned at tip, longer than sepals

Stout, straight, longer than sepals

M ore stout, straight, often shorter than sepals

Inflorescence

Extremely lax

Lax

Usually very dense

Ripe seeds

Capsules (a) subsp. leptoclados, (b) subsp. serpyllifolia, (c ) subsp. lloydii.

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Plant Crib

ASPLENIUM The evolution and genetical relationships (e.g. cytology and enzyme content) in the temperate northern hemisphere species of Asplenium are one of the best studied in any group of ferns. The taxonomy of the European species, partially clarified by a study of chromosome numbers and the role of hybridisation, is confused by the plasticity of the leaf morphology, which can be affected by environmental factors and lead to problems of identification, at least between closely related taxa. The following groups can give problems: the A. adiantum-nigrum complex, the A. obovatum aggregate, and the A. trichomanes aggregate.

1. Asplenium adiantum-nigrum complex A considerable amount of variation especially in leaf morphology is present within the complex. The tetraploid taxon, A. adiantum-nigrum, can be similar to the two diploid parental taxa (A. cuneifolium Viv., A. onopteris) from which it has evolved. Plants on serpentine, originally thought to be diploid and reported as A. cuneifolium (Roberts & Stirling 1974; Jermy et al. 1978) have since been shown to be tetraploid (Sleep et al. 1978). Vogel et al. (1997) using chloroplast DNA techniques elucidated the maternal lineage of the two forms: that with ‘cuneifolium’ maternal genes [A. adiantum-nigrum subsp. silesiacum Milde (syn. subsp. corrunense (H. Christ) Rivas-Mart.; et sensu C. N. Page 1997)]; and that with ‘onopteris’ maternal genes [A. adiantum-nigrum subsp. adiantum-nigrum]. The ultimate rank and choice of epithet will not be an easy decision as a number of contending names are available but we suggest they are recorded for the Atlas under the subspecies names given above.

The other diploid parent A. onopteris is a South Atlantic/M editerranean plant recorded in the British Isles so far only from Ireland. Some forms of A. adiantum-nigrum can look superficially very similar; but the spore size will distinguish them. The hybrid between the two, A. × ticinense D.E. M ey., has been recorded with the parents in Cork (Roberts & Scannell 1977) and Kerry (A. Paul, pers. comm.); both are sterile. A. adiantum-nigrum L. subsp. adiantum-nigrum

A. adiantum-nigrum subsp. silesiacum Milde

A. onopteris L.

Leaf blade (Figs e-h)

Triangular or triangularovate, 2-3 pinnate or 2pinnatisect, deep mid-green, shiny

Broadly triangular or triangular-ovate, 2-3 pinnate or 2-pinnatisect, deep midgreen, ± dull

Triangular, 3-pinnate or 3pinnate-pinnatisect, tapering to a caudate apex, fresh midgreen, very shiny

Pinnae

Up to 10 cm long, apex acute to slightly tapered

Up to 5 cm long, apex subacute to acute

Up to 12 cm long, tapered to a long-caudate apex

Ultimate segments

Ovate-elliptic to oblanceolate, with convex curved margins narrowed to the base, often deeply cut, apex toothed and acute

Wedge-shaped, base narrowly to broadly cuneate, the margins straight or recurved, toothed at the broadly rounded apex

Narrowly lanceolate, tapered, with an acute apex and teeth

Spores

(21-) 31–37 (-45) µm [mean 34 µm], dark, sooty-brown

(21-) 31–37 (-45) µm [mean 34 µm], mid to dark brown

(21-) 26–31 (-39) µm [mean 28 µm], pale straw

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Plant Crib

Leaves of Asplenium (a) A. adiantum-nigrum subsp. adiantum-nigrum, (b) A. adiantum-nigrum subsp. silesiacum, (c) A. onopteris. (Del. R. H. Roberts [a, b] & P. Edwards [c]).

References

Jermy, A. C., Arnold, H. R., Farrell, L. & Perring, F. H. (1978). Atlas of ferns of BPS/BSBI, London. Page, C. N. (1997). Ferns of Britain and Ireland. (Edn 2) Cambridge University Roberts, R. H & Scannell, M. J. P. (1977) Irish Naturalists’ Journal 19: 75-77. Roberts, R. H. & Stirling, A. McG. (1974). Fern Gazette 11: 7-14.

the British Isles. Press, Cambridge.

Sleep, A., Roberts, R. H., Souter, J. I. & Stirling, A. M cG. (1978). Fern Gazette 11: 345-348. Vogel, J. C., Russell, S. J., Barrett, J. A. & Gibby, M . (1997). Pp. 313-327 in Pteridology in perspective (eds Camus et al.). Royal Botanic Gardens, Kew.

2. Asplenium adiantum-nigrum / A. obovatum Asplenium obovatum Viv. subsp. lanceolatum (A. billotii F. W. Schultz) is an autotetraploid derivative of A. obovatum subsp. obovatum, a SW European and M editerranean diploid taxon not yet recorded for the British Isles. The latter tends to be smaller and the leaflets less cut (Fig. d). Young or small plants of subsp. lanceolatum may be very similar and it would be difficult to determine without a chromosome count or DNA analysis. Nevertheless, the diploid subspecies may be present in warm habitats on the SW coasts of both Britain and Ireland and suspected plants should be reported. A. obovatum subsp. lanceolatum hybridises with A. adiantum-nigrum to form A. × sarniense Sleep and has been recorded in the Channel Islands (Sleep & Ryan 1973). It could be expected in Britain and Ireland where the two species grow together. The plants show intermediate morphology (Fig. b); some plants show hybrid vigour, others being lax and somewhat ‘scruffy’. The stalked, well-spaced pinnules seen in A. × sarniense give the plant a jizz and makes it distinct from either of its parents. For those recording in the spring, a possible hybrid will show green, although often ragged, leaves of last year’s growth (a lanceolatum character) when the young leaves are unfurling, somewhat earlier than more typical A. obovatum is showing signs of growth. In these cases check spores later in the season.

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Plant Crib A. adiantum-nigrum

A. obovatum Viv. subsp. lanceolatum (Fiori) P. Silva

A. obovatum subsp. obovatum

Habit

Plant rarely with a wellformed rosette but with few leaves

Plants usually forming a compact rosette of many (>15) leaves amongst old persistent leaves & petioles

Plants forming less dense rosettes (up to 6 - 8 leaves)

Leaves

10-25 (-50) cm, triangular or triangular-ovate, 2-3 pinnate or 2-pinnatisect

10-30 cm, lanceolate, 2pinnate

10-25 cm, lanceolateoblong, 2-pinnatepinnatifid

Petiole

Only the swollen base close to rhizome retained when leaf dies

Base not swollen but whole petiole persistent for several years

Base not swollen, usually not persistent when leaf dies

Pinnae (Figs. a, c & d)

Up to 15 pairs, up to 10 cm long, the lowest pair the longest, ± triangular-ovate to broadly trowel-shaped

Up to 20 pairs, up to 7 cm long, the lowest pair shorter than the one above it, linear-lanceolate to oblong, pinnate for most of their length

Up to 12 pairs, up 4 cm long, the lowest pair shorter than the one above it, ovate-triangular, pinnate only in lower half

Ultimate segments

Ovate-elliptic to oblanceolate, often deeply cut, acute, not mucronate, not narrowed to a stalk

Oblong with acute mucronate teeth, stalked

Suborbicular, ± crenate, with obtuse or rounded teeth only faintly mucronate, stalked

Sorus

1-3 mm, linear-oblong, closer to the midrib than to the segment margin

1-2 mm, linear-oblong, closer to the margin than the segment midrib

1-2 mm, oblong, closer to the margin than the segment midrib

Exospore length

(21-) 31–37 (-45) µm [mean 34 µm]

(28-) 33– 41 (-49) µm [mean 36 µm]

(22-) 28–32 (-40) µm [mean 30 µm]

See Figs a-c

Lowest acroscopic pinnules of middle pinna of (a) Asplenium adiantum-nigrum, (b) A. × sarniense Sleep, (c) A. obovatum subsp. lanceolatum, (d) A. obovatum subsp. obovatum. (Del. P. Ryan [a-c], F. Rumsey [d]).

Reference

Sleep, A. & Ryan, P. (1973). La Société Guernesiaise Report & Transactions 1972: 212-223. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

3

Plant Crib 3. Asplenium trichomanes aggregate This aggregate is represented in the British Isles by a diploid (subsp. trichomanes) and two tetraploids (subsp. quadrivalens and subsp. pachyrachis [A. csikii Kümmerle]). In Europe other variations are known, given subspecific rank in Flora Europaea (Viane, Jermy & Lovis 1993) but detailed genetical work at the molecular level suggests that these taxa should be accepted at the species level (J. Vogel, pers. comm.). Spore size and stomatal length are helpful to divide the group up to ploidy level. A species typically found on rock outcrops, ledges and man-made walls, occasionally on hedgerows and banks in deeper soil, both in open and in shade. Macro leaf characters are affected by the micro-environment and make identification difficult (see Lovis 1978). The chemical composition of the rock substrate is important: subsp. trichomanes is a definite calcifuge, on acid (i.e. silicious) rocks and on dry stone walls where completely free of mortar; subsp. quadrivalens is a calcicole and the common species on walls with mortar, and on limestone, basalt and but sometimes on other rock types that may have only very low calcium content; and subsp. pachyrachis is found on limestone and then usually on more vertical faces and in crevices on steeper rocks but also on mortared walls, especially of old castles. The latter subspecies was only recently recorded for Britain (Rickard 1989) and more records may be made. Subsp. trichomanes may be under-recorded but the majority of specimens in British and Irish herbaria have been identified by J. D. Lovis as subsp. quadrivalens. The hybrid between subsp. quadrivalens and subsp. pachyrachis (A. trichomanes nothossp. staufferi Lovis & Reichst.), and between subsp. quadrivalens and subsp. trichomanes (A. trichomanes nothossp. lusaticum (D.E. Mey.) Lawalrée have been recorded and should be looked for where the parents grow together (e.g. on drystone walls with a mortared capping). They often show ‘hybrid vigour’ and have abortive spores.

Habit and leaves of Asplenium trichomanes (a) subsp. trichomanes, (b) subsp. quadrivalens, (c) subsp. pachyrachis.

References

Lovis, J. D. (1978). In Jermy et al., Atlas of ferns of the British Isles: 60. BSBI/BPS, London. Rickard, M. H. (1989). Pteridologist 1: 244-248. Viane, R., Jermy, A. C. & Lovis, J. D. (1963). Flora Europaea 1 (ed. 2): 18-23. Cambridge University Press, Cambridge.

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Plant Crib Asplenium trichomanes subsp. trichomanes

Subsp. quadrivalens Subsp. pachyrachis (H. D.E. Mey. emend. Lovis Christ) Lovis & Reichst.

Stipe

Thin, wiry, glossy, at first black-brown, rapidly becoming bronze-red-brown, persistent long after the pinnae have been shed; not easily broken

Thick, glossy, blackish or dark brown and remaining so throughout the season, eventually becoming dull, often persistent but less so than in ssp. trichomanes, the dead leaf tending to break off just above stipe base; not easily broken

Thick, glossy, blackish or dark brown and remaining so throughout the season, eventually becoming dull, often persistent but less so than in ssp. trichomanes, the dead leaf tending to break off just above stipe base; easily broken

Longest scales

3.5 mm with a central redbrown stripe (see Note 1)

5 mm with a central dark brown stripe (see Note 1)

5 mm with a central dark brown stripe (see Note 1)

Pinnae

Up to 8 mm long, orbicular (in exposed sites) to oval or rhombic and asymmetric (in more sheltered sites), with a distinct stalk, more widely spaced than in subsp. quadrivalens, mostly alternate, those in the upper part obliquely inserted, distinctly longitudinally ridged, often curling under along the wavy margin whilst turning up at the apex; hyaline border absent

Up to 11 mm long, more crowded than in spp. trichomanes (but well separated in shady situations), oblong (even in exposed sites), symmetrical, almost sessile, mostly opposite, with a square insertion, lacking longitudinal ridges, the lateral margins tending to roll under but the apex flat; hyaline border indistinct

Up to 11 mm long, often ± overlapping (but more separated in shady situations), oblong (even in exposed sites) to subtriangular or even hastate, usually with a distinct auricle on the acroscopic margin, symmetrical, almost sessile or sometimes shortly stalked, alternate at least below, with a square insertion, margin often deeply crenately toothed and wavy; hyaline border ± conspicuous

Sorus

Up to 2 mm long, 4-6 per pinna

Up to 3 mm long, 4-9(-12) per pinna

Up to 3 mm long, 4-9(-12) per pinna

Indusium

Narrow and delicate

Broad, conspicuous and more persistent than subsp. trichomanes

Broad, conspicuous and more persistent than subsp. quadrivalens

Exospore mean length

(23-) 28-32 (-34) µm (see Note 2)

(26-) 32-38 (-47) µm (see Note 2)

(26-) 32-38 (-50) µm (see Note 2)

Stomata guard-cell

Mean length 32-40 µm (see Note 2)

Mean length 40-48 µm (see Note 2)

Mean length 40-49 µm (see Note 2)

Notes 1. Colour of scales best seen immersed in water or weak glycerin. 2. When measuring spores and stomata guard cells at least 25 should be measured to arrive at the mean.

Authors

A. C. Jermy, F. J. Rumsey & J. C. Vogel, January 1998. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib ATHYRIUM DISTENTIFOLIUM, A. DISTENTIFOLIUM VAR. FLEXILE AND A. FILIX-FEMINA Athyrium distentifolium is a plant of higher mountains in Scotland where snow lies late into the season and on north-facing ledges on the more acid range of rock types. A. filix-femina can also be found on adjacent ledges especially if exposed to the south. A. distentifolium var. flexile (A. flexile Newman) is a rare endemic form usually found within populations of the type variety on skeletal soils over medium-sized block scree, or where spring melt-water percolates, at c. 750m or above (McHaffie 1997). Regarded by some (e.g. Stace’s New Flora; Page 1997) as a species, and a detailed study is being carried out by H. McHaffie.

Athyrium. filixfemina (L.) Roth

A. distentifolium Tausch A. distentifolium var. ex Opiz var. distentifolium flexile (Newman) Jermy

Leaves

Up to 120 cm; dull, mid- to somewhat blue-green; ellipticlanceolate, tapered ± abruptly to an acuminate apex; 2or 3-pinnate (Fig. a)

Up to 75 cm; pale to yellowish green; ellipticlanceolate, tapered to an acuminate apex; 2- or almost 3-pinnate, margins of the ultimate segments touching giving a less lacy appearance than in A. filix-femina (Fig. b)

Up to 35 cm; pale to blue green; ± elliptic, tapered gradually to an acute apex, 2-pinnate (Fig. c)

Petiole

1/4 - 1/2 length of leaf, green, or purplish red

About 1/4 length of leaf, pale yellow-green, almost translucent, often pinkish or straw-coloured at base

1/5 or less length of leaf, yellow-green or reddish, markedly deflexed just below the blade

Pinnae

Linear-lanceolate, tapered to a fine apex; decrescent (decreasing in length downwards) and ± opposite and remote below

Linear-lanceolate, tapered to a fine apex; decrescent and ± opposite and remote below

Linear-lanceolate to subtriangular, abruptly tapered to a subacute or obtuse apex; lower pinnae alternate, usually contiguous, often deflexed, not markedly decrescent

Pinnules

Linear-lanceolate, apex obtuse-acute, pinnatisect, or pinnate-pinnatifid, ± contiguous, touching the rachis

Linear-lanceolate, apex obtuse to acute, pinnatisect, ± contiguous, touching the rachis

Ovate-oblong, apex obtuse, often tridentate, pinnatifid or coarsely toothed, wellspaced throughout

Sorus

Oblong to linear, close to vein, those on larger pinnules often J-shaped,

± round and appearing more uniformly arranged on the pinnule than in var. flexile

± round, frequently in the lower 1/2 of the leaf only and often with fewer sporangia and less uniformly

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Plant Crib straddling the vein

arranged on the pinnule than in var. distentifolium

Indusium

Linear, oblong or Jshaped, membranous

Imperfectly formed and soon lost or absent entirely

Imperfectly formed and soon lost or absent entirely

Spores

Minutely scabrid

Finely ridged

Finely ridged

Silhouettes of leaves of Athyrium (a) A. filix-femina, (b) A. distentifolium var. distentifolium, (c) A. distentifolium var. flexile.

References

McHaffie, H. (1997). Pteridologist 3: 88-91. Page, C. N. (1997). Ferns of Britain and Ireland. (ed. 2). Cambridge University Press, Cambridge.

Authors

A. C. Jermy & H. McHaffie, January 1998.

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Plant Crib

AVENA The four species of Avena most often found are not difficult to separate once is familiar with the characters to look for. In the species where spikelets disarticulate, this is obvious because the florets break off from the rhachilla with a clean, elliptical scar at the base. In A. fatua, each floret has a scar so that the spikelet disarticulates between each of the florets. In A. sterilis, only the lowest floret has a scar, so that at maturity the spikelet disarticulates at the top of the lowest joint of the rhachilla just above the glumes and the florets all fall off attached together as one unit. In the remaining species, the crop plants, A. sativa and A. strigosa, the florets have no scar and the species requires threshing for dispersal. Any attempt to separate the florets from the glumes or from each leaves an irregular fracture and not a smooth scar. A detailed account of Avena in V.c. 46 is given by Chater (1993). Stace’s New Flora also includes the rare alien A. barbata.

1 1

At least the lowest f loret with a prominent ov al smooth dehiscence scar at the base (Fig. a), the spikelet disarticulating abov e the glumes at maturity 2 Florets without a dehiscence scar, the spikelet not disarticulating abov e the glumes at maturity 4

2 2

All f lorets with a dehiscence scar and falling separately at maturity Only the lowest f loret with a dehiscence scar and the florets falling as a group

3 3

Glumes 30-50 mm long; lowest lemma 25-40 mm long Glumes 25-30 mm long; lowest lemma 20-25 mm long

A. fatua L. (A. sterilis L.) 3

A. sterilis L. subsp. sterilis

A. sterilis L. subsp. ludoviciana (Durieu) Gillet & M agne 4

Tip of lemma with 2 f inely -awned teeth, the straight awns 3-9 mm long (these in addition to the central geniculate awn 20-35 mm long arising f rom the middle of the back of the lemma)

4

Tip of lemma with 2 acute teeth or shortly mucronate (with or without an awn on the back)

A. strigosa Schreb. A. sativa L.

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Plant Crib

a

b

Florets of (a) A. fatua, (b) A. sativa.

Reference

Chater, A. O. (1993). BSBI Welsh Bulletin 55: 7-14.

Author

T. A. Cope, M arch 1988, updated A. O. Chater, December 1997.

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Plant Crib

BETULA

1. Betula pendula / B. pubescens The taxonomy of the genus Betula is disputed, and opinions differ as to the extent of hybridisation. Intermediates between B. pendula and B. pubescens are, however, common and widespread. They are intermediate in leaf-shape, pubescence, bark of trunk and twigs, habit, and fruiting catkins. Most intermediates seem fully fertile and probably back-cross, since the intermediates are not always clearly separable from the parent species. When collecting material please include catkins and mature leaves, and if possible, photograph the tree to show bark and shape. Seedlings of both species are hairy. To deal with the problem of intermediates, Atkinson & Codling (1986) developed a discriminant function, using three easily measured leaf characters, which has been adopted in Stace’s New Flora and is not repeated here. Although hybrids undoubtedly exist in natural and semi-natural populations (Brown et al. 1982), they are probably very uncommon. The hybrid is similar in morphology to B. pubescens and a description is given by Kennedy & Brown (1983). The parental species are distinct in chromosome number (B. pendula 2n=28 and B. pubescens 2n=56). The F1 hybrid has 42 chromosomes although some of the hybrids discussed by Brown et al. (1982) appear to be back-crosses as they have a range of chromosome numbers. 1

1

2

Bark at f irst shiny and red-brown, later pinkish-white with horizontal, broad, pale-grey bands and some dark-grey scaling patches, f inally white with large, black diamonds, of ten deeply -f issured at the base into small, black, knobbly plates; young twigs glabrous, slender and pendent, with numerous peltate, non-odorous resin glands or warts; leav es usually sharply biserrate with prominent primary teeth, glabrous; nutlet glabrous; total width of nutlet with wings 3-5 mm, the upper edge of the wings surpassing the stigmas; f ruit scales with broad lateral lobes curv ing towards the base B. pendula Roth (B. verrucosa) Bark at f irst red-brown as in B. pendula, becoming smooth, grey ish-white, v ariably banded horizontally grey or brown (sometimes with f ine, grey lacework patterns), of ten remaining brownish until mature, but nev er with black diamonds; young twigs usually ± pubescent, spreading or ascending, with or without resinous glands; leav es irregularly -serrate, without prominent primary teeth, usually hairy , at least on the v eins beneath; nutlet puberulent at apex; nutlets with narrower wings (total width 2-4 mm), the upper edge of the wings not or hardly surpassing the stigmas; f ruit scales with lobes straight or curv ing towards the apex 2 Tree usually with a single stem; y oung twigs usually conspicuously pubescent; buds not v iscid; leaves 3-4 cmB.

pubescens Ehrh. subsp. pubescens 2

Shrub or small tree, of ten with sev eral stems; y oung twigs glabrescent, cov ered with brown, sticky , resinous, pleasantlysmelling glands; buds v iscid; leav es of ten less than 3 cm long. Most readily distinguished in spring when the unfolding buds hav e a pleasant, resinous smell

B. pubescens subsp. tortuosa (Ledeb.) Nyman

B. pendula

B. pubescens

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Plant Crib References

Atkinson, M. D. (1992). Journal of Ecology 80: 837-870. Atkinson, M. D. & Codling, A. N. (1986). Watsonia 16: 75-87. Gardiner, A. S. (1984). Proc. Royal Society Edinburgh 85B: 13-26. Kennedy, D., Brown, I. R. & Williams, D. A. (1982). Watsonia 14: 133-145. Kennedy, D. & Brown, I. R (1983). Watsonia 14: 329-336.

Authors

M. J. Wigginton & G. G. Graham (1981); updated M. D. Atkinson, December 1997.

2. Betula × intermedia (B. pubescens × B. nana) This hybrid is probably under-recorded in Scotland. On the whole the leaves look like a small B. pubescens Ehrh., but are quite variable between populations, and plants seem largely sterile.

B. nana L.

Reference

B. × intermedia Thomas ex Gaudin

De Groot, W. J., Thomas, P. A. & Wein, R. W. (1997). J. Ecology 85: 241-264.

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Plant Crib

BRASSICA JUNCEA / SINAPIS ARVENSIS Brassica juncea and the very variable Sinapis arvensis are easily confused. Brassica juncea is not uncommon as a bird-seed or oil-seed casual, and is overlooked. The differences between are shown overleaf: Sinapis arvensis L.

Brassica juncea (L.) Czern. & Coss.

Habit

Coarse with spreading branches, dark green

Slender with erect branches, light green, sometimes slightly glaucous

Hairs (stem and leaves)

Coarsely hairy to glabrescent

Glabrous or sparsely hairy below

Sepals

Held at an angle of (40-)60-150° (Fig. a)

Held at an angle of 20-70°(Fig. c)

Valves of dried fruit

3-7 strong veins, the mid-vein only just the strongest (Fig. b)

1 strong central vein and finer weak laterals (Fig. d)

Beak of fruit

7-16 mm long, 0-1 seeded

(4-)5-9(-12) mm long, sterile

Flowers and fruits of Sinapis arvensis (a, b) and Brassica juncea (c, d)

References Rich, T. C. G. (1987). BSBI News 47: 25-27. Rich, T. C. G. (1988). Wild Flower Magazine 411: 29-32.

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Plant Crib

BROMOPSIS BENEKENII / B. RAMOSA B. benekenii looks very similar to B. ramosa and is consequently probably overlooked in rocky woods and ravines. In flower, the species can be distinguished using the characters below, but vegetative material cannot, as yet, be separated satisfactorily. Useful jizz characters are that B. benekenii is taller (about 20 cm) (at least in the west; they are reported as shorter in Beech woods in the east), and the inflorescences are swept to one side and appear denser as they have more spikelets with shorter branches. B. ramosa is usually shorter, with graceful, open, slender, arching inflorescences. The latter nearly always grows with or near B. benekenii. Some populations are more intermediate in characters, and on dry ledges B. benekenii may have 1-3 branches only. Festuca gigantea can look similar to both in habit, but is glabrous. B. benekenii (Lange) Holub: Lowest node of panicle with (1-)3-5 branches (some of which may have only one spikelet); scale minutely hairy (×20 lens). B. ramosa (Huds.) Holub: Lowest node of panicle with 2(-4) branches (each usually with 2 or more spikelets); scale hairy with ciliate margins.

a

b

Scales from lowest node (a) B. benekenii, (b) B. ramosa.

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Plant Crib

CALAMAGROSTIS Five species of Calamagrostis occur in Britain and Ireland, which can be identified as follows:-

For full details of C. canescens, C. stricta and their hybrid in N England, see Crackles (1994, 1995). Note that C. stricta is protected in Northern Ireland under Schedule 8 of Wildlife (NI) Order 1985 and must not be collected.

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Plant Crib C. canescens (F. H. Wigg.) Roth

C. epigejos (L.) Roth

C. purpurea (Trin.) Trin.

C. stricta (Timm) Koeler

C. scotica (Druce) Druce

Glumes

4-6 mm long very variable × 0.75-0.85 mm wide

4-6 mm long, very variable × 0.75-0.85 mm wide

4-6 mm long, very variable × c. 1 mm wide

3-4.5 mm long, short, × 1.1-1.2 mm wide

4-6 mm long, very variable, × 1-1.2 mm wide

Callous hairs

Longer than lemma

Longer than lemma

Longer than lemma

Shorter than lemma

Shorter than lemma

Nodes

3-5

Usually 3

5-8

2-3

2-3

Ligules

2-4 mm

4-9 mm

7-14 mm

1-3 mm

1-3 mm

Upper surface of leaf

Scabrid, hairy

Scabrid, not hairy

Scabrid and hairy in UK.

Scabrid and shortly hairy (many English plants are glabrous)

Scabrid and shortly hairy

Position of awns on lemmas

Within upper 7% of lemma

Within upper 3060% of lemma

Within Within upper 9-40% upper 50of lemma 80% of lemma

Within upper 6880% of lemma

References Crackles, F. E. (1994). Watsonia 20: 51-60. Crackles, F. E. (1995). Watsonia 20: 397-404. Author

O. M . Stewart, January 1988, minor updates 1997.

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Plant Crib

CARDAMINE BULBIFERA The alien form of the Nationally Scarce plant C. bulbifera (L.) Crantz with broad, strongly toothed leaves (forma ptarmicifolia (DC.) O. E. Schulz) sometimes escapes from gardens, and should be recorded as distinct from the native form, forma bulbifera (Showler & Rich 1993). The native form is also grown in gardens.

forma ptarmicifolia

Reference

forma bulbifera

Showler, A. J. & Rich, T. C. G. (1993). Watsonia 19: 231-245.

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Plant Crib

CAREX For the identification of Carex, the BSBI Handbook Sedges of the British Isles 2nd ed. (Jermy, Chater & David 1982) is essential. A third edition which will describe and illustrate the hybrids is in preparation. The notes below merely emphasize or supplement the information given in the Handbook. References to a series of papers by R. W. David detailing the distribution of most of the rarer species can be found in the Handbook, and recent maps of many species are given in the Scarce Plants and Aquatic Plants. M ost species show great variation in vegetative characters, and fruiting material is often essential for identification. Sterility of utricles, or total non-flowering, is often caused by environmental factors rather than by hybrid origin; non-emergence of the anthers is a more reliable indicator of the latter but some hybrids (e.g. C. divulsa × C. muricata; O’M ahony 1989) regularly have emergent anthers. Abnormalities in the inflorescence are not uncommon and can cause difficulties when using the keys. The groups dealt with are as follows: 1 C. paniculata etc. (p. 342) 6 C. rostrata etc. (p. 346) 2 C. vulpina etc. (p. 343) 7 C. strigosa etc. (p. 346) 349) 3 C. muricata etc. (p. 343) 8 C. flacca etc. (p. 347) 4 C. disticha etc. (p. 344) 9 C. binervis etc. (p. 347) 5 C. acutiformis etc. (p. 344) 10 C. flava etc. (p. 348)

11 C. digitata etc. (p. 348) 12 C. caryophyllea etc. (p. 13 C. limosa etc. (p. 350) 14 C. nigra etc. (p. 350) 15 C. bigelowii etc. (p. 351).

Stomata The distribution of stomata on the leaf surfaces can be a very useful identification character. The stomata are arranged in rows, and can usually be seen as minute white dots with the aid of a ×20 or even a ×10 lens. It is especially useful as a field character on fresh specimens, and the stomata become slightly less easy to see in dried material. In the field it is often a much easier character to use than some of the more traditional ones such as the number of stigmas. If a microscope is available, it is a good idea to confirm what you are looking at with a selection of species, either by stripping off bits of epidermis or, more easily, by making an impression of the surface with nail varnish. Generally speaking, the leaf surface with the most stomata becomes concave on drying, so that for example in C. nigra, in which the stomata are mostly confined to the upper surface, the leaf margins roll inwards on drying, while in C. acuta, which has the stomata confined to the lower surface, the leaf margins roll outwards on drying. In hybrids, the distribution of stomata appears to combine that of the two parents, so that, for example, C. × turfosa (C. elata × C. nigra) have stomata abundant on both surfaces. In some species such as C. flacca and C. panicea (in which the stomata incidentally are not diagnostically helpful) it is papillae rather than stomata that show as white dots, but the papillae seem largely confined to the vicinity of the stomata so the character can still be assessed with a lens. The character is especially valuable for distinguishing C. rostrata from C. vesicaria, and from their hybrid; vegetative C. lasiocarpa from C. rostrata; C. bigelowii from C. nigra; and C. acuta from Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib C. aquatilis and C. nigra.

1. Carex paniculata / C. appropinq uata / C. diandra Three closely related species, commonly tussock-forming, are given in descending order of size. Difficulties of identification really only arise with depauperate specimens; starved C. paniculata may resemble C. appropinquata and non-tussocky forms of C. appropinquata approach similar forms of C. diandra. The most certain distinction is in the utricle. C. paniculata L.

C. appropinquata Schumach.

C. diandra Schrank

Utricle s

Greenish- to blackishbrown with a broad serrulate wing in the upper half

Greyish-brown, abruptly narrowed into an unwinged beak

Blackish-brown and shiny, more evenly tapered with an unwinged beak and markedly split at the back, the halves overlapping

Basal sheath s

Dark brown, shiny, not splitting into fibres

Black, matt, splitting into hair-like fibres (not always apparent unless dry)

Black- or grey-brown, not fibrous

Leaves (2-)4-7 mm wide, dark, usually dull green

1-2 mm wide, yellowgreen

1-2 mm wide, greyish or bronzy green

Inflore- Compound; spikes scence pedunculate

Compound; spikes pedunculate

Simple; spikes sessile

Glume s

Reddish (especially on drying)

Brown or purplebrown, hyaline

Greyish- or orangebrown

There is a hybrid, C. × solstitialis Figert, intermediate between C. paniculata and C. appropinquata and wholly sterile. Depauperate specimens of C. paniculata may be taken for the hybrid with C. remota (C. × boenninghausiana Weihe) but this has a long-extended inflorescence with the small spikes widely separated and conspicuous bracts. For C. diandra when not forming tussocks, see 4 below (page 342).

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Plant Crib 2. Carex vulpina / C. otrubae C. vulpina is a rare but probably overlooked species, which should always be confirmed by microscopic examination of the epidermis of the utricle. C. vulpina L.: Stems strongly winged; ligule truncate, shorter than width of leaf, its free border overlapping edge of leaf; inner face of leaf sheath transversely wrinkled; lowest bract always short, with blackish-brown auricles; all glumes usually dark or rusty brown; utricles minutely papillose (×20 lens), the epidermis with ± isodiametric cells. C. otrubae Podp.: Stems scarcely winged; ligule pointed, at least as long as width of leaf, not overlapping edge of leaf; inner face of leaf sheath smooth; lowest bract often long and setaceous, usually pale at base; all glumes pale reddish- or orange-brown; utricles smooth, the epidermis with elongated cells.

C. vulpina

C. otrubae

Surface view of centre of adaxial face of utricle.

3. Carex muricata aggregate The descriptions in the key below are of the extreme forms of the two subspecies of C. divulsa which are very distinct, but many intermediates occur, at least in southern Britain (please record intermediate plants as ‘intermediates’). The hybrid C. divulsa × C. muricata has been found in Ireland (O’M ahony 1989). 1

1

2 2

Utricles with nut set well abov e the corky swollen base, and with narrow elongated serrate beak, the whole 4.5 mm or more long; glumes acuminate, ± tawny , giv ing, with the long-beaked utricles, a shaggy look to the inf lorescence; leav es and stems slightly f leshy , ligule sof t, narrow, 4-8(-10) mm long; roots, and sometimes (but not inv ariably) basal sheaths, ligules, and glumes tinged v inous-purple C. spicata Huds. (C. contigua Hoppe, C. muricata auct. non L.) Utricles with nut arising f rom base of utricle, with less pronounced beak, of ten less than 4.5 mm long; glumes acute or acuminate; ligule less than 4 mm long; roots, basal sheaths, ligules and glumes not purplish tinged 2 Inf lorescence not more than 3 cm long, spikes ± contiguous; ligule nearly ov ate, slightly longer than broad; base of utricle f lat or rounded with the nut set close upon it 3 Inf lorescence distinctly interrupted, with interv als of 1-3 cm between the lowest two spikes; ligule as long as or shorter than broad; utricle narrowed at base as well as at beak (i.e. diamond shaped) 4

3

Flowering stems erect, rigid; glumes markedly shorter than utricles, dark, contrasting in colour with the utricles until these ripen and darken; utricles rounded, with a broad margin or f lange, narrowing abruptly into a short beak; strongly calcicolous, f lowering May

3

Flowering stems f lexuous; glumes ± as long as utricles, y ellow or pale brown, concolorous with unripe utricles but becoming white and then contrasting with the brown ripe utricles; utricles ov oid, narrowly margined, narrowing ev enly into the beak; calcif ugous, f lowering June

C. muricata L. subsp. muricata (C. pairaei F. W. Schultz subsp. borealis Hyl.)

C. muricata L subsp. lamprocarpa Celak. (C. pairaei F. W. Schultz, C. bullockiana Nelmes) Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 4

4

Plant f laccid, dark- or grey -green; leav es of ten as long as the drooping f lowering-stem; inf lorescence very interrupted, up to 10 cm long or ev en more with interv als of 2 cm or more between the lowest spikes; utricles 3.5-4(-4.5) mm, appressed to the stem-axis, becoming grey ish-black when fully mature C. divulsa Stokes subsp. divulsa Plants robust, erect, bright y ellow-green; leav es shorter than f lowering stem; inf lorescence not more than 6 cm long, with the interv als of less than 2 cm between lowest spikes; utricles (4-)4.5-4.8 mm long, markedly div aricate, becoming redbrown when mature

C. divulsa Stokes subsp. leersii (Kneuck.) W. Koch (C. leersii F. W. Schultz non Willd., C. polyphylla Kar. & Kir.) 4. Carex disticha / C. arenaria / C. divisa / C. diandra C. disticha Huds.

C. arenaria L.

C. divisa Huds. C. diandra Schrank

Leaf sheath

Inner face herbaceous with narrow hyaline margin at apex

Inner face wholly hyaline turning brown

Inner face wholly hyaline

Inflorescence

Untidy, narrowed in middle

Untidy, generally Compact, pyramidal ellipsoid or pyramidal (spikes crowded at apex, often with long overlapping bract (note 1))

Compact, cylindrical

Termina Entirely female l spike

Entirely male

M ale at top and female below

M ale at top and female below

Ripe utricles

Broadly winged, greenish-brown

Unwinged, pale brown

Unwinged, blackish-brown, shiny

Narrowly winged, redbrown

Inner face wholly hyaline

Note 1. The bract over-topping inflorescence, given in many keys as the distinguishing character of C. divisa, is NOT invariably present.

5. Carex acutiformis / C. riparia / C. acuta These three sedges cannot be reliably separated vegetatively by the width of the leaf. Whilst C. acuta leaves are always relatively narrow, both C. acutiformis and C. riparia can reach 26 mm wide. The ligule shape, although distinctive in some cases, is often of intermediate character.

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Plant Crib The structure of the leaf provides useful diagnostic characters. The leaves have air-filled tubes (aerenchyma) with cross-walls or diaphragms at intervals dividing them into sections. The pattern of the diaphragms is characteristic and may readily be seen through the hyaline inner surface of the sheath just below the ligule, as illustrated. The dimensions are tabulated below. Carex riparia Curtis

C. acutiformis Ehrh.

C. acuta L.

Leaf width

5-20(-26) mm

5-20(-26) mm

4-6 mm

Ligule length

5-10 mm

5-20 mm

4-8 mm

Ligule shape

Rounded

Acute

Obtuse

Aerenchyma width

0.4-0.7 mm

0.3-0.5 mm

c. 0.4 mm

Inter-diaphragm distance

1.5-2.0(-3.0) mm

3.0-8.2 mm

M ore than 5.0 mm

With familiarity it is not necessary to take measurements and there is an additional character which is indicative in fresh material. On the fully formed leaves of C. riparia, the aerenchyma pattern is equally easily seen above and below the ligule, and it is also visible on the outside of the leaf. In C. acutiformis and C. acuta the pattern becomes obscured just above the ligule and is not apparent on the outside of the sheath. However, C. acutiformis and C. riparia often cannot be reliably separated vegetatively and, certain identification depends on having inflorescences.

a

b

Leaf sheaths and ligules (a) C. riparia, (b) C. acutiformis.

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Plant Crib C. acutiformis

C. riparia

Male glumes

Obtuse to subacute, purplishbrown when fresh

Acuminate, dull brown when fresh

Utricles

3.5-5 mm, somewhat flattened, strongly ribbed, greyish-green

5-8 mm, somewhat inflated, obscurely ribbed, brown or yellowish-brown

Beak of utricle

Usually emarginate or weakly bifid

Strongly bifid

Authors

A. O. Chater & R. M . Walls, December 1997.

6. Carex rostrata / C. vesicaria / C. lasiocarpa C. rostrata and C. vesicaria are very variable and can often be extremely difficult to separate in the absence of good ripe fruit; vegetatively the distribution of stomata is the best character. C. rostrata Stokes

C. vesicaria L.

Leave s

2-7 mm wide, flat and folded to caniculate or inrolled, usually glaucous above; stomata confined to or much more abundant on upper surface

4-8 mm wide, flat or folded, midor yellowish-green above; stomata confined to lower surface

Ligule

Shorter than width of leaf

As long as or longer than width of leaf

Utricle s

3.5-6.5 mm, usually more or less patent, 4-8 mm, ascending, gradually abruptly contracted from ovoid body narrowed from ovoid-ellipsoid into very slender, parallel-sided beak body into tapering beak

C. lasiocarpa Ehrh., which often grows with C. rostrata and when not flowering can be confused with it, has grey-green, not glaucous leaves with the stomata confined to the lower surface.

7. Carex strigosa / C. sylvatica / C. pendula, vegetative In flower the upright, unstalked inflorescences of C. strigosa are quite diagnostic, but it is the ligule in winter that is distinctive and makes the separation from C. sylvatica and young C. pendula relatively simply. The ligules of C. strigosa are short, with a slight point, free at the edges, and usually, and crucially, strikingly asymmetrical. Those of C. sylvatica are short, rounded and appressed, whereas

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Plant Crib C. pendula are always pointed and elongated to some degree. When they start to grow in spring and flower these differences are somewhat blurred. C. strigosa, although sometimes abundant, is often found in discreet colonies, even down to one or two plants. Its leaves, intermediate in size between those of C. pendula and C. sylvatica, have a more yellowish-green tinge, and become brown and tatty at the ends. They also lie flat in a flaccid, limp way that is diagnostic but difficult to describe.

Carex sylvatica Huds.

Carex strigosa Huds.

Reference

Pearman, D. A. (1995). BSBI News 68: 11.

Author

D. A. Pearman, January 1998.

Carex pendula Huds.

8. Carex flacca / C. panicea The difference between these species are slight on paper but should rarely cause difficulties in the field once they are known, at least in fruiting material. Colour of leaves, often used in keys, is not a reliable character. C. flacca Schreb.

C. panicea L.

Basal sheaths and rhizome scales

Dark purplish-brown

Pale greyish-brown

Leaves

With midrib channel usually extending to extreme tip

With midrib channel ceasing before tip, the apical few mm trigonous, flat above

Lowest bract

Sheath 0-3(-10) mm long

Usually with a sheath 10-15 mm long

Utricles

Symmetrical, papillose, densely packed so that rachis of spike is not visible

Asymmetrical, smooth or minutely papillose, loosely arranged so that rachis is usually visible

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Plant Crib 9. Carex binervis / C. distans / C. hostiana / C. laevigata / C. punctata These five species are closely related and can be similar in general appearance. They are best separated on a combination of characters, among which colour of basal sheaths, leaves and glumes is very important. Characters unique to one species are underlined. C. binervis Sm.: leaves dark green, orange-tinged like basal sheaths when dead or injured, evenly tapered to apex; female glumes black or dark purplish-brown; utricles ascending at 45-60° to axis of spike, dark purplish-brown but often partly green. C. distans L.: leaves dark or greyish-green, dull brown like basal sheaths when dead, evenly tapered to apex; female glumes pale brown or pale reddish-brown; utricles ascending at 45-60°, dull greenishbrown. C. hostiana DC.: leaves light or yellowish-green, greyish-brown like basal sheaths when dead, usually abruptly contracted into a parallel-sided vein-less tip several mm behind apex; female glumes dark, usually reddish-brown, with conspicuous silvery-hyaline margins (absent in other species); utricles ascending at 45-60°, yellowish- to brownish-green. C. laevigata Sm.: leaves light or yellowish-green, the widest usually 8-10 mm wide (rarely, except sometimes in C. punctata, over 6 mm in the other species), dull brown like basal sheaths when dead, evenly tapered to apex; female glumes pale reddish-brown; utricles ascending at 45-75°, greenish or brownish. C. punctata Gaudin: leaves yellowish-green, brown or reddish-brown like basal sheaths utricles at 75-90°, shiny yellowish-green (whitish when young), abruptly contracted into beak (more gradually narrowed in other species).

10. Carex flava group The revision of this group by Schmid (1983) (which was adopted by Stace 1991, 1997) so far as species and subspecies are concerned, has, by making most of the British and Irish taxa subspecies of C. viridula M ichaux, reduced the need to separate the taxa as rigidly as was attempted in the past. The following key applies only to the taxa as they occur in our area. The old names are given in square brackets. 1 1 2

Ripe utricles 6-6.5 mm, gradually narrowed into a beak 2-3 mm long; leav es about as long as stems, 3.5-7 mm wide; ligule 3-5 mm C. flava L. Ripe utricles 1.75-5 mm, with beak up to 2 mm long; leav es 1.5-5 mm wide; ligule c. 1 mm 2 Leav es of f ertile tillers not more than ½ as long as stems, 2-3(-4) mm wide; utricles 3.5-5 mm, distinctly curved (as well as being def lexed in lower part of spike), with beak occupy ing at least 1/3 of total length C. viridula subsp.

brachyrrhyncha (Celak.) B. Schmid [C. lepidocarpa Tausch] 2

At least some leav es of f ertile tillers more than ½ as long as stems, 1.5-5 mm wide; utricles 2-4 mm, straight or weakly curv ed (though often def lexed), with beak occupying less than 1/3 of total length 3

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Plant Crib 3

Stems usually curv ed; leav es f lat; lowest spike of ten widely separated f rom the others; utricles 3-4 mm, with beak usually 1 mm or more

3

Stems straight; leav es usually caniculate; f emale spikes usually all clustered at apex of stem; utricles 2-3(-3.5) mm, with beak less than 1 mm C. viridula subsp. viridula [C. serotina M érat]

C. viridula subsp. oedocarpa (Andersson) B. Schmid [C. demissa Hornem.]

Sell & M urrell (1996) have all the taxa as subspecies of C. flava and include four not in Stace’s New Flora (subspecies jemtlandica, bergrothii, scotica and pulchella). European experts tend neither to accept the first two as occurring in the British Isles, nor to accept the latter two as subspecies. A thorough revision of the whole group is needed. Hybrids with C. hostiana (C. × fulva Gooden.) Hybrids of subsp. brachyrrhyncha, subsp. oedocarpa and subsp. viridula with C. hostiana are frequent. They can be recognised by the spikes being tapered above and rather appressed to the stem with often erect bracts, the empty utricles, and the anthers which remain undehisced and hidden under the male glumes; which subspecies is the parent can best be judged by whichever is present in the locality (there is rarely more than one of them present).

11. Carex digitata / C. ornithopoda These two species are instantly distinguished from all other sedges as the inflorescences arise laterally from the base of shoots rather than terminally. When flowering or fruiting these species should be easily distinguishable, for the lowest spike of the inflorescence of C. digitata is clearly separated from the one above it, whereas in C. ornithopoda all the spikes originate from almost the same point; the inflorescence of C. digitata is sometimes at least tinged with crimson while that of C. ornithopoda is straw-coloured; and in C. digitata the female glumes are as long as the utricles whereas in C. ornithopoda they are markedly shorter. When the plants are in the vegetative state separation is not easy, for the intensity of the red coloration of the basal sheaths and the breadth and degree of hairiness of the leaves (the distinctions usually quoted) are relative. However the sheaths of C. digitata are, in general, more deeply and genuinely crimson (as opposed to mid- or darkgreen). Furthermore, the new shoots of C. digitata are very distinctive. They begin to appear in October and are then tinged with deep red and tipped with green. In M arch they elongate and arch over at the tips, presenting a highly characteristic fountain-shape. None of these characters are found in C. ornithopoda. A good time to spot the latter is M ay when the young pale green leaves appear forming dense tufts in the middle of the clumps.

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Plant Crib

Author

Carex ornithopoda Willd.

Carex digitata L.

Leaves

Deeper green, 5-20 cm, glabrous

Lighter green, up to 25 cm, usually sparsely-hairy on upper surface

Inflorescence

1/8-1/10 length of stem, compact, ± digitate

1/5-1/4 length of stem

Male glumes

c. 2.5 mm, obovate

5 mm, rounded or even emarginate at apex

Female spikes

2-3, 5-10 mm, 2-4 flowered (rarely more), ± sessile

1-2, 10-20 mm, 5-10 flowered, pedunculate

Female glumes 2.0-2.5 mm

3.0-4.0 mm

Ripe utricles

3.0-4.0 mm, less tapered below, about equalling glumes

3.0-4.0 mm, much exceeding glumes

M . J. Wigginton & G. G. Graham (1981), updated T. C. G. Rich, 1998.

12. Carex caryophyllea / C. ericetorum / C. montana / C. pilulifera The two common species can easily be distinguished in flower and fruit as the lowest bract has a sheath in C. caryophyllea but not in C. pilulifera, and vegetatively as the free margin of the ligule is entire in the former and minutely fimbriate (×20 lens) in the latter. C. montana has a very distinctive growth habit, making widening tufts that often die out in the middle like fairy rings, with a woody rootstock covered with the reticulately fibrous remains of dead leaves and crimson-tinged basal sheaths (sometimes also seen in C. pilulifera); the leaves are soft, upright and pale whitish-green (but not glaucous).

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Plant Crib C. caryophyllea Latourr.

C. pilulifera L.

C. ericetorum Pollich

C. montana L.

Basal sheaths

Brown or blackish-brown

Brown or reddish-brown

Dark brown or blackish

Crimson

Stems

Rigid, erect

Wiry, often curved and prostrate

Rigid, erect

Filiform, drooping or prostrate

Leaves

M id-green, often Bronze-green, recurved, often recurved, glabrous glabrous

Usually dark green, with scarious margin, rigid, recurved, glabrous

Pale whitishgreen, soft, usually upright, with sparse hairs on upper surface at least when young

Ligule (×20 lens)

Entire

M inutely fimbriate

± Entire

M inutely fimbriate

Lowest bract

With a sheath 35 mm long

Without a sheath

Without a sheath

Without a sheath

Male spikes

Clavate

Cylindrical

Cylindrical

Cylindrical

Female glumes

Reddish-brown or greenish, acute or apiculate

Reddish-brown

Purplish-brown to black, with fimbriate scarious margin

Reddish-purple to black, without a scarious margin

Utricles

Obovoidellipsoid, tomentose

Obovoidsubglobose, minutely tomentose

Obovoidsubglobose, minutely tomentose

Obovoidpyriform, minutely tomentose

13. Carex limosa / C. magellanica / C. rariflora C. limosa and C. magellanica are often confused, and C. rariflora. is also included here as it is similar in general habit. C. limosa grows in very wet bogs, often in standing water, producing tufts of few, inrolled, glaucous leaves on long rhizomes which grow sideways in a distinctive fashion; prostrate shoots late in the season may have leaves much wider than the earlier leaves. C. magellanica grows in wet but not submerged Sphagnum bogs on level shelves of moorland, producing larger more compact clumps of Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib broader, flat, yellow-green leaves. C. rariflora occurs with Sphagnum in wet alpine acid flushes/mires and on the silty banks of the headwaters of burns in the Cairngorms. The characteristic little fans of curved greyish leaves might be taken for a miniature iris. C. magellanica is protected in Northern Ireland under Schedule 8 of the Wildlife (NI) Order 1985. 1 1

2 2

Lowest spike largely f emale but with 1 or f ew male f lowers at base; f emale glumes much narrower than ripe utricles; lowest bract usually ov er-topping inflorescence; leaves 1.5-4 mm wide, y ellow- or apple-green, f latC. magellanica Lam. Lowest spike entirely f emale; f emale glumes almost as wide as or wider than ripe utricles; lowest bract shorter than inf lorescence; leav es 1-2(-4) mm wide, grey -green or glaucous, flat, in-rolled or folded 2 Male spikes 3-4 mm wide, with 5-8 flowers; leav es flat C. Male spikes 5-7 mm wide, with 7-20 flowers; leav es folded or in-rolled

rariflora (Wahlenb.) Sm. C. limosa L.

14. Carex nigra / C. elata / C. acuta / C. aq uatilis / C. recta C. nigra, the commonest species of this group, is extremely variable and hybridises with all the other members. (Crosses are possible between every other pair, see Wallace in Stace (1975) Hybridisation, and most are partially fertile.) C. elata is best recognised by its tussocky habit and short, stiff bracts; C. aquatilis by its vein-less utricles, brittle stems and long, leaf-like bracts; C. acuta differs from C. nigra chiefly in the long bracts and general size, and from C. aquatilis most reliably in the veined utricles, and from both by the stomata being mostly confined to the lower surface of the leaf. 2 3

1 1

Plant f orming stout tussocks Plant f orming stands of separate tufts

2

Rhizomes v ery short and erect within the tussocks; basal sheaths splitting to f orm f ibrillae; leav es with stomata confined to lower surf ace; stems stout, rigid; lowest bract much shorter than inf lorescence, rigid C. elata All. Rhizomes longer, emerging f rom the tussocks; basal sheaths entire, membranous; stems slender, pliable; leav es with stomata mostly conf ined to upper surf ace, sometimes also a f ew scattered on lower; lowest bract v ariable but usually not much shorter than or somewhat exceeding inflorescence, pliable C. nigra (tussock form)

2

3 3 4

Leav es 1.5-3 mm wide; leav es with stomata mostly conf ined to upper surf ace; lowest bract shorter than or slightly exceeding inflorescence; male spikes 7-50 mm C. nigra (L.) Reichard Leav es 3-7 mm wide; lowest bract much exceeding inflorescence; male spikes 20-100 mm 4 Leav es bright green and shiny beneath; stems brittle, usually breaking when f olded, smooth; leav es with stomata mostly conf ined to upper surf ace; male glumes appressed to utricles giv ing spike a neat appearance; utricles veinlessC.

aquatilis Wahlenb. (note 1) 4

Leav es dull green beneath; stems not breaking when f olded, rough abov e; leav es with stomata mostly conf ined to lower surf ace; males glumes stiff, often giv ing spike a prickly appearance; utricles faintly veinedC. acuta L.

Note 1. C. recta Boott, which probably originated as a hybrid between C. aquatilis and the Scandinavian C. paleacea, occurs only in NE Scotland. It is distinguished by the lower female glumes bearing an arista at least half as long as the body of the glume; stomata are abundant on both surfaces of the leaf.

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Plant Crib 15. Carex bigelow ii / C. nigra Specimens of C. nigra from high altitudes, when stunted or sterile, are often confused with C. bigelowii. C. bigelowii Torr. ex Schwein: Rhizome scales shiny, coriaceous, entire, persistent reddish- or purplishbrown (often best seen at the base of aerial stems); stems conspicuously stout, rigid; utricles vein-less; stomata confined to the lower surface of the leaf. C. nigra (L.) Reichard: Rhizome scales less conspicuous less coriaceous, often soon becoming fibrous and usually paler; stems proportionally more slender; utricles distinctly though often faintly veined; stomata are confined to, or are much more abundant, on the upper surface of the leaf. Reference

O’M ahony, T. (1989). Irish Naturalists’ Journal 23: 137-141.

Authors for Carex unless otherwise stated A. O. Chater & R. W. David 1988, revised 1997 by A. O. Chater.

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Plant Crib

CATAPODIUM 1. Catapodium marinum / C. rigidum Branched forms of C. marinum (L.) C. E. Hubb. are not uncommon around the coast and have been misrecorded as C. rigidum (L.) C. E. Hubb., especially in the north (pers. comm. A. J. Silverside 1997). Branches form in the larger specimens, perhaps growing in luxuriant conditions. If in doubt, the larger spikelets and flower parts should distinguish them from C. rigidum (see Stace’s New Flora).

(a) C. marinum

(b) C. marinum branched form

(c) C. rigidum

2. Catapodium rigidum Two subspecies of C. rigidum (L.) C. E. Hubb. can be distinguished as below, updated from Trist (1979). In Stace’s New Flora they are treated as varieties. Variation in height may be partly due to nutrient-rich soil, so check other characters too. Subsp. rigidum is widespread. Subsp. majus (C. Presl) F. H. Perring & P. D. Sell occurs near the coast in S and W Britain and in Ireland. Subsp. rigidum

Subsp. majus

Height

3-12 cm

18-38 cm

Leaf

25-40 mm long × 0.8-1.5 mm wide

60-130 mm long × 1-3.5 mm wide

Ligule

1-1.5 mm

2-3.5 mm

Panicle

3.5-4 cm, outline pyramidal

3-9 cm, outline lanceolate

Spikelet 3.5-5 mm s

4.5-6 mm

Reference

Trist, P. J. O. (1979). Watsonia 12: 261-262.

Author

P. J. O. Trist, February 1991. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

CERASTIUM 1. Cerastium alpinum / C. arcticum M ost British material of Cerastium arcticum and C. alpinum can be easily separated on hair characters but variation in C. arcticum may cause problems. Typical C. alpinum is clothed with matted, flexuous, long white, tapering hairs which imparts a soft greyish appearance to the plant. C. arcticum tends to be pubescent with shorter, straighter, yellowish, tapering hairs, the plant appearing much greener. Some plants may contain a variable number of hairs that approach the alpinum type and may cause difficulty in separation from C. alpinum. Nearly all British material of C. arcticum was recognised as var. alpinopilosum by Hultén (1956) and was considered to be the product of introgression with C. alpinum. Specimens from only two Scottish mountains (Ben Nevis and Beinn Bhann in Applecross) were identified as C. arcticum var. arcticum; these completely lack any hint of the woolly hairs which were considered by Hultén to indicate genes of C. alpinum. A population in the Eastern Cairngorms mentioned in Stace’s New Flora bear very distinctive short, patent, non-tapering, finger-like hairs. The seed morphology agrees with C. arcticum but it appears to merit separate taxonomic recognition. A seemingly less variable character is the structure of the seed coat. The surface of C. alpinum seeds are quite acutely tubercled whilst the surface of those of C. arcticum are rugose or wrinkled (this character is ignored by Hultén, was described in CTM but disappears again in Stace’s New Flora). Further, the capsules of C. arcticum are usually straight whilst they are, in most cases, curved in the upper half in C. alpinum. A distinctive but less easy character to describe is the shape of the flower when fully open. The petals of C. alpinum remain straight or at most with the tips very slightly flared whilst the flowers of C. arcticum, open widely with the tips of the petals reflexed; this imparts a distinctly campanulate shape to the flower. Sterile hybrids are found within populations of C. arcticum on several Scottish hills. These have been identified as C. alpinum × C. fontanum from Coire an Lochain in the Cairngorms but is rather questionable as the former is extremely rare in this predominantly acid mountain range. Generally C. arcticum and C. alpinum are separated ecologically with C. arcticum favouring acid or at least hard basic rocks whilst C. alpinum is strongly calcicolous and is confined to softer calcareous rocks or niches influenced by basic flushing. C. alpinum L.: Plant densely covered with soft, white flexuous hairs; flowers non or very slightly campanulate in anthesis; seeds tuberculate; calcicole. C. arcticum Lange: Plant pubescent with predominantly short yellowish hairs; flowers campanulate in anthesis; seeds rugose; on acid and harder basic rocks.

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Plant Crib Reference

Hultén, E. (1956). Svensk Botanisk Tidskrift 50: 411-495.

Author

P. Lusby, January 1998.

2. Cerastium fontanum subspecies In the account of Cerastium fontanum Baumg. in Flora Europaea (Wyse Jackson 1993) four subspecies are distinguished, two of which, subsp. vulgare and subsp. scoticum, occur in Britain or Ireland. Stace’s New Flora recognises these two subspecies, plus a third, subsp. holosteoides, which is treated as a variety of subsp. vulgare in Flora Europaea. For the purposes of this short account all taxa are placed at the rank of subspecies. Subsp. vulgare is by far the commonest subspecies both in Britain and Ireland and throughout the rest of the range of the species, and is found in a wide range of natural, semi-natural and man-made habitats. It is an extremely variable taxon with respect to its morphology and chromosome number, and a number of well-defined subordinate taxa are recognised, the most commonly occurring in Britain and Ireland being the type, var. vulgare. M orphological characteristics of subsp. vulgare var. vulgare include the following: whole plant usually moderately to densely pubescent; flowering stems (3-)12-40(-60) cm long; leaves of flowering stem (5-)7-20(-25) mm long; inflorescence frequently many-flowered, sometimes fewflowered, with (1-)8-17(-35) flowers; sepals (4-)5.5-7(-7.5) mm long; petals mostly shorter to only slightly longer than sepals (0.75-1.2(-1.35) times as long as sepals); capsules 8-12(-13) mm long; seeds mostly 0.6-0.9 mm long. The range of morphological variation that subsp. vulgare var. vulgare displays in many characters is such that in order to confidently distinguish it from the other subspecies found in Britain and Ireland it is necessary to utilise a combination of characters. Subsp. holosteoides sensu Stace is an uncommon plant in Britain and Ireland that has been known from several sites since the last century. It is always associated with rivers, where it grows on grassy riverbanks and in marshy flood-plain meadows in, or just upstream of, those sections of the river under tidal influence. It is characterised by its glabrous or very sparsely pubescent leaves and its sparsely pubescent flowering stems which either have hairs arranged in a single line between the internodes, or which (rarely) lacks hairs altogether. It tends also to have longer sepals ((6.5-)7-8(-9) mm) and capsules ((11-)12.5-14.5(-16) mm) than subsp. vulgare var. vulgare and subsp. scoticum, larger seeds ((0.8-)0.850.95(-1.2) mm) than the former and more flowers in the inflorescence (mostly 16-20) than the latter. It intergrades with subsp. vulgare var. vulgare and in some sites only intermediates are known. Plants from sand dune sites are frequently sparsely pubescent; they differ, however, in several respects from glabrescent plants of riverine sites and are best referred to subsp. vulgare. It should be noted that the calyx and capsule measurements cited under subsp. holosteoides in Stace’s New Flora 1st ed. (1991) refer to subsp. vulgare; this has been amended in the 2nd ed. (1997). Subsp. scoticum is a well defined taxon, described as a subspecies in 1967 (Jalas & Sell 1967), but known to botanists since the last century. It is the rarest of the subspecies, being restricted to three small ‘serpentine’ sites, situated within 1 km of each other at an altitude of 860 m near the head of Glen Doll in Angus, Scotland. It is distinguished from other subspecies of C. fontanum through a combination of its long, showy petals (1.4-1.7 times as long as sepals), short sepals ((4.5-) 5.5-6(-6.5) mm), capsules (9-12.5 mm), flowering stems (3-12(-16) cm) and flowering stem leaves ((5-)7-8(-10) mm), its large seeds ((0.8)0.85-1.15 mm long), few-flowered (1-3(-6)) inflorescences, frequently sparsely pubescent or glabrous Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib leaves, and sepals which are strongly keeled at the base. Disregarding the differences in habitat and range, there is little chance of confusing subsp. scoticum and subsp. holosteoides, the latter being a considerably more robust plant with generally much larger parts and a smaller petal:sepal length ratio. Subsp. scoticum was formerly thought to occur in West Sutherland but plants from there are referable to subsp. vulgare. Some plants of high altitudes in Britain resemble subsp. scoticum with regard to their petals which may be conspicuously longer than the sepals (up to 1.35 times). However, they differ in other respects and are best referred to a long-petalled form of subsp. vulgare. Key for the identification of C. fontanum subspecies: 1 1

2

Petals 1.4-1.7 times length of sepals; inf lorescence with 1-3(-6) f lowers; sepals usually strongly keeled at base; flowering stems short, 3-12(-16) cm subsp. scoticum Jalas & P. D. Sell Petals shorter to slightly longer than sepals (v ery rarely up to 1.35 times); inf lorescence mostly with 8-20 flowers; sepals mostly weakly keeled; f lowering stems short or tall, (3-)12-40(-90) cm 2 Flowering stems and upper leav es moderately to densely pubescent; f lowering stems with hairs all round; sepals (4-)5.5-7(7.5) mm long; capsules 8-12(-13) mm long; seeds mostly 0.6-0.85(-0.9) mm longsubsp. vulgare (Hartm.) Greuter &

Burdet 2

Flowering stems and upper leav es v ery sparsely pubescent or glabrous; f lowering stems with hairs arranged in one row, or glabrous; sepals (6.5-)7-8(-9) mm long; capsules (11-)12.5-14.5(-16) mm long; seeds (0.8-)0.85-0.95(-1.2) mm long

subsp. holosteoides (Fr.) Salman, Ommering & de Voogd Glandular hairs are very rarely encountered in plants of C. fontanum from Britain and Ireland - shortpetalled plants (petals up to 1.5(-1.6) times as long as sepals) with glandular hairs are almost always referable to one of the annual species, C. diffusum, C. glomeratum, C. pumilum or C. semidecandrum, or in the uplands to hybrids involving C. fontanum and C. alpinum or C. arcticum. Seed tubercle width is sometimes employed to discriminate some of the subspecies of C. fontanum; its usefulness is limited, however, because of the wide range of variation in this character shown by subsp. vulgare, and because of the practical difficulties many workers have in accurately measuring lengths of 0.1 mm and less. References Jalas, J. & Sell, P. D. (1967). Watsonia 6: 291-318. Wyse Jackson, M . B. (1992). Botanical Journal of the Linnean Society 109: 325-328. Wyse Jackson, M . B. (1993). Flora Europaea 1:171-172 (2nd ed.). Author

M . B. Wyse Jackson, January 1998.

3. Cerastium brachypetalum / C. glomeratum These two species can be easily separated from C. diffusum, C. pumilum and C. semidecandrum in that they have long eglandular hairs on the sepals projecting beyond the apex. C. brachypetalum Pers. is a rare plant known from Kent and the Northants./Beds. border but could easily occur elsewhere. It looks similar to the other annual Cerastium species and does not stand out as different until it is known. Plants lack glands, and the fruits are held on long pedicels usually at an oblique angle. It tends to look slightly more greyish-brown due to the hairs than the other species. C. glomeratum Thuill. is sticky-glandular and has dense, crowded inflorescences with pedicels usually shorter than the sepals in fruit. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 4. Cerastium diffusum / C. pumilum / C. semidecandrum These species are easily distinguished from C. glomeratum and C. brachypetalum in that they lack hairs projecting beyond the sepal tips. Do not confuse bracts with leaves or sepals; bracts at the final dichotomy only should be examined. The characters, in order of importance, are bracts, fruiting pedicels and margins of sepals. C. diffusum Pers.

C. pumilum Curtis

C. semidecandrum L.

Bracts

Entirely herbaceous

Narrow scarious margin and tip

At least upper bracts with broad scarious margins and tips

Flowers

Usually 4-merous, sometimes 5-merous

5-merous

5-merous

Petals

About 1/5 bifid, ¾ as long as sepals

About ¼ bifid, as long as sepals

Slightly notched, 2/3 as long as sepals

Pedicel s

M uch longer than sepals Larger than sepals, at first throughout, erect in fruit recurved then nearly erect with slight curve just below capsule

Usually equalling or slightly exceeding sepals, at first sharply deflexed from base, later erect

Sepals

Scarious margin narrow

Scarious margin fairly broad

Scarious margin broad

Glandular, usually reddish-tinged

Glandular, green

General Often very sticky habit glandular, dark green

C. pumilum is often (but not always) reddish-flushed and the flowers are noticeably white as the petals are about as long as sepals. It occurs in open calcareous rubble, anthills, rocks, etc. (map in Scarce Plants). C. diffusum is very characteristic of coastal cliffs and dunes. It also occurs on sandy ground inland, and should be looked for in spring where Plantago coronopus grows on roadsides. C. semi-decandrum is the most widespread of the three. All three species vary markedly in abundance from year to year, and two, sometimes three, can be found growing together. Authors

R. M . Burton & T. C. G. Rich, December 1997.

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Plant Crib

CHENOPODIUM A number of the less well-known Chenopodium species such as C. murale, C. opulifolium and C. urbicum may be declining, under-recorded as this is a difficult genus, or both. Leaf outlines of species perhaps passed over as variable / polymorphic C. album (cf. Cole 1961) or C. rubrum are given below to help with search images. In the field C. glaucum L., C. hybridum L. and C. vulvaria L. do look obviously different from common species. The orientation of the seeds in the fruiting perianth is an important character to learn (horizontal =short and fat - Fig. a; vertical = ovate-obovate - Fig. b). It is not difficult to see with a lens in fruiting plants, but is difficult to use in plants without seed. As seed characters (colour, size, patterns on the surface of the testa) are important for identification, vouchers should preferably have ripe seed, with colour notes on the parts of the plant.

1. Chenopodium chenopodioides / C. rubrum Chenopodium chenopodioides (C. botroydes Smith) is an annual of bare, open, seasonally exposed, dry, brackish mud in ditches, hollows and poached turf on saltings and grazing marshes, mostly in SE England (Scarce Plants). It is easily over-looked, partly because of its similarity to C. rubrum with which it often grows, and partly because of its often small size and late flowering season. Plants should be looked for in the above habitats including recently exposed mud where ditches have been cleaned out. The characteristic reddish coloration develops most strongly in September-October, making this a fruitful time to look for it and it is probably not worthwhile looking for it before July. It varies in abundance from year to year and has a good seed bank so it may reappear in old sites; full population details of this Red Data Book species should be recorded.

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Plant Crib

Author

C. chenopodioides (L.) Aellen

C. rub rum L..

Habit

Prostrate to decumbent, deep vermilion

Erect, bright red, often scarlet or orange

Leaves

Noticeably thick and fleshy, tinged Relatively less fleshy, strongly to reddish underneath when young, the weakly toothed lower very blunt, almost rounded, un-toothed (weakly toothed in robust specimens)

Calyx on lateral flowers

Closed over the fruit to hide seeds (fused to ± apex)

Fused to c. ½ way revealing seeds

R. FitzGerald, January 1998.

2. Chenopodium urbicum / C. rubrum C. urbicum L. may be under-recorded or declining, or both. It looks rather like C. rubrum being tall and ± glabrous with lobed leaves (cf. illustrations below) but is usually green (not red-flushed) and has horizontal black (not brown) seeds.

Leaves of C. urbicum

3. Chenopodium murale and C. opulifolium C. murale L. and C. opulifolium Schrader ex Koch & Ziz may be under-recorded (over-looked as C. album?) or declining, or both. Leaf outlines of both species are given below to help with search images. Compared to C. album, C. murale tends to have more deeply toothed leaves and is darker green and often decumbent at the base. C. opulifolium is very mealy and has ovate to broadly-ovate leaves compared with ovate-lanceolate leaves in C. album.

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Plant Crib

a

b Leaves (a) C. murale (b) C. opulifolium

4. Chenopodium ficifolium / C. album / Atriplex patula Once the distinctive oblong shape of the leaves with large basal lobes is known, it is relatively easy to pick out C. ficifolium Smith from the ubiquitous but highly variable C. album L.. Examine leaves on the middle stem of the plants. In fruit, C. ficifolium has close radially elongate pits on the testa, whilst C. album has smooth or faintly striate pits (see photomicrographs in Stace‘s New Flora). It is also easy to mistake Atriplex patula L. for C. ficifolium when young leaves only are present (the latter tends to have acute lobes and ovate leaves). The highly clumped distribution map in the original Atlas coupled with the more recent widespread recording suggests that C. ficifolium was significantly under-recorded for the Atlas. It occurs in very similar places to C. album.

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Plant Crib

Chenopodium album

Chenopodium ficifolium

Atriplex patula

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Plant Crib

CHRYSOSPLENIUM ALTERNIFOLIUM / C. OPPOSITIFOLIUM / GLECHOMA HEDERACEA / SIBTHORPIA EUROPAEA All these species are winter-green, and there should be no confusion over flowering or non-flowering plants despite the generally similar leaves. C. oppositifolium L. leaves are ± entire, oblong and in opposite pairs. The leaves of C. alternifolium L. are single, stalked, large and round, with a distinct dip in the middle of each lobe, and a notch at the base. Vegetatively, C. alternifolium can only be confused with Glechoma hederacea L. but it can be distinguished by the little bristles rather than the hairs on the upper surface, by the dip in the lobe and by the less distinct vein pattern on the underside. Sibthorpia europaea L. leaves are tiny by comparison, c. 0.5-1(-1.5) cm diameter (usually 2 cm or more in other species).

Sibthorpia europaea

Author

Glechoma hederacea

Chrysosplenium alternifolium

C. oppositifolium

D. A. Pearman, January 1998.

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Plant Crib CONIFERS Collecting notes

Cones usually need to be dried and kept separately from the pressed foliage, preferably in envelopes or bags as many disintegrate or shed seeds. Label these separately, with a cross reference, as they will be kept separate in a herbarium. Press side shoots plus a terminal shoot and bud, and photograph or describe bark and shape of crown. It is virtually impossible to prevent needles of Picea, etc., from falling during drying. Key to taxa

Over most of our countryside, except in parts of Scotland, conifers are foreign introductions, much neglected by our botanists especially in County Floras. They are, however, an important part of our vegetation, particularly in their relationship to some of our birds and insects. In large gardens and arboreta are to be found a considerable proportion of the world's species. Naming these is a difficult problem. They should be covered by the account in S. M. Walters et al., The European Garden Flora vol. 1 (1986), but I find the keys inadequate and the illustrations do not help identification. The fourth edition of W. Dallimore and A. B. Jackson, A Handbook of Coniferae and Ginkgoaceae, revised by S. G. Harrison, contains much valuable information, but it is a large book difficult to find one's way about in. Perhaps the best book to use is A. Mitchell, A Field Guide to the Trees of Britain and Northern Europe ed. 2 (1978). Although some of the colour characters are difficult to understand and the information is sometimes rather disjointed, it gives the refreshing impression that the author is writing what he himself sees and is not copying from others who themselves have copied from one another. Arboriculturalists have selected and perpetuated many peculiar and often grotesque sports, some of which are mentioned by Mitchell and many superbly illustrated in D. M. van Geldersen and J. R. P. van Hoey Smith, Conifers (1986) and Conifers: the illustrated encyclopaedia 2 vols. (1996). There are large numbers of conifers to be found in plantations, woodland, shelter belts, hedgerows, copses, parks, cemeteries and churchyards throughout our islands (a provisional checklist is given by C. Crook (1997) BSBI News 75: 42-47). They are found in important areas for conservation and should be properly recorded. The following key includes all those species I think are most likely to be found in these places. It can be used in conjunction with Mitchell (1978). It has been written after I have spent the winter looking at living specimens of many of the species. I have also consulted much literature. Nevertheless the key is still not entirely satisfactory and any improvements would be welcome. 1 Leaves all small and scale-like, usually more or less appressed to the twigs and shoots 2 1 At least some leaves needle-like, linear, acicular (needle or awl-like) or spine-like, scale-leaves rarely present as well 11 2 Twigs rounded or 4-sided, the scale-leaves even on all sides 2 Twigs flat, the facial scale-leaves usually flat, rarely keeled, the lateral scale-leaves keeled Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Pdfs created by Chris Barron.

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3 4

Plant Crib Cupressus 3 Scale-leaves entire, obtuse at apex, without resin gland on back Cupressus macrocarpa Hartw. ex Gordon 3 Scale-leaves finely toothed, acute at apex, with a conspicuous gland on back exuding white resin Cupressus glabra Sudw Chamaecyparis / Cupressocyparis 4 Young shoots only slightly flat, nearly 4-sided 4 Young shoots distinctly flat

× Cupressocyparis leylandii (A. B. Jack. & Dallim.) Dallim. 5

5 Terminal shoot usually 'whip-like', drooping; cones globose, the peltate scales touching only at the margins 5 Terminal shoot erect; cones ovate to oblong, their scales overlapping

6 9

6 Scale-leaves without white markings on the lower surface, when crushed with a heavy unpleasant smell Chamaecyparis nootkatensis (D. Don) Spach 6 Scale-leaves with white or bluish markings on the under-surface, when crushed with a strong resinous aroma 7 7 Scale-leaves obtuse 7 Scale-leaves acute

Chamaecyparis obtusa (Siebold & Zucc.) Endl. 8

8 Lateral scale-leaves keeled, overlapping the rhomboidal, smaller facial scale-leaves Chamaecyparis lawsoniana (A. Murray bis) Parl. 8 Lateral scale-leaves boat-shaped, the facial ones flat Chamaecyparis pisifera (Siebold & Zucc.) Siebold & Zucc. Thuja 9 Foliage in vertical sprays, without scent when crushed; scale-leaves the same colour on both sides Thuja orientalis L. 9 Foliage spreading in flat sprays, aromatic when crushed; scale-leaves a different colour on lower sides from upper 10 10 Scale-leaves with conspicuous glands, yellowish- or bluish-green beneath, smelling of cooked apples with cloves when crushed Thuja occidentalis L. 10 Scale-leaves with inconspicuous glands with narrow streaks of greenish-white beneath, with a powerful aroma of apples or pineapple Thuja plicata D. Don 11 Leaves always solitary 11 Leaves in clusters

12 39

12 Leaves opposite or in whorls of 3 12 Leaves spirally arranged, some sometimes appearing to be in 2 rows

13 18

13 Leaves with distinct white stripes (stomatal bands) on the upper side 13 Leaves without distinct white stripes above

l4 17

Juniperus 14 Leaves all acicular 14 Both acicular and scale-like leaves present

15 16

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Plant Crib 15 An erect or spreading bush; leaves 8-20 x c. 1 mm, apex gradually tapered to a long point; fruit globose Juniperus communis L. subsp. communis 15 A procumbent bush; leaves 4-10 x c. 1.5 mm, apex more suddenly contracted to a shorter point; fruit longer than broad Juniperus communis L. subsp. nana (Hook.) Syme 16 Scale-leaves obtuse 16 Scale-leaves acute

Juniperus chinensis L. Juniperus virginiana L.

17 Leaves with whitish stripes beneath 17 Leaves green on both sides

(juvenile forms of Chamaecyparis) (juvenile forms of Thuja)

Araucaria 18 Leaves ovate-triangular 25-30 mm long, stiff and prickly and covering the stem Araucaria arucana (Molina) K. Koch 18 Leaves not as above 19 19 Young shoots yellowish, brownish or reddish 19 Young shoots greenish

20 33

20 Leaves attached directly to the twigs, and when removed twig smooth 20 Leaves attached to a small projection and when removed twig rough

21 23

Abies 21 Leaves bluish-green on upper side with 4-6 rows of stomata; young shoots with short reddish hairs Abies procera Rehder 21 Leaves dark shining green on upper side and stomata usually absent; young shoots with short whitish or brownish hairs 22 22 Leaves 20-60 mm; buds resinous; cones 5-12 cm, bracts included Abies grandis (D. Don) Lindl. 22 Leaves 15-30 mm; buds not or only slightly resinous; cones 10-20 cm, bracts exerted Abies alba Mill. 23 Leaves without a petiole 23 Leaves with a distinct petiole

24 29

Picea 24 Leaves flat, with 2 bands of stomata only on the upper surface 24 Leaves tetragonal, with stomata on all 4 sides

25 26

25 Young shoots glabrous; leaves 15-25 mm, pungent (i.e. sharply pointed); cones 6-10 cm Picea sitchensis (Bong.) Carrière 25 Young shoots hairy; leaves 8-18 mm, obtuse and mucronulate; cones 3-6 cm Picea omorika (Panvic) Purk. 26 Leaves 6-10 mm, obtuse 26 Leaves 10-25 mm, acute

Picea orientalis (L.) Link 27

27 Young shoots densely pubescent with short hairs; cones 6-8 cm. Picea abies (L.) H. Karst. subsp. obovata (Ledeb.) Hultén 27 Young shoots glabrous or with scattered minute hairs; cones 10-18 cm 28 28 Cone scales with a truncate and erose or emarginate apex Picea abies (L.) Karsten subsp. abies var. abies 28 Cone scales with an in-curved acumen at the apex Picea abies (L.) H. Karst. subsp. abies var. acuminata Beck Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Pdfs created by Chris Barron.

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Plant Crib Tsuga / Pseudotsuga 29 Leaves 10-25 mm; petiole appressed to the shoot; buds small and rounded or shortly pointed 29 Leaves 20-35 mm; petiole at an oblique angle to the shoot; buds long and narrow, acuminate

30 31

30 Young shoots with long and short hairs intermixed; buds rounded at apex; leaves parallel-sided Tsuga heterophylla (Raf.) Sarg. 30 Young shoots shaggy with long hairs; buds pointed at apex; leaves tapering towards the apex Tsuga canadensis (L.) Carrière 31 Leaves with strong, sweet, resinous aroma when crushed, dark yellowish or medium green on upper surface; cones 7-10 x 2.5-4.5 cm, with 40-50 scales, bracts erect Pseudotsuga menziesii (Mirbel) Franco subsp. menziesii 31 Leaves often smelling of turpentine when crushed, dark bluish- or greyish-green on upper surface; cones 4.5-8.0 x 2-3 cm, with up to 30 scales, bracts often prominently reflexed 32 32 Leaves not 2-ranked but all round the old twigs; cone bracts reflexed Pseudotsuga menziesii subsp. glaucescens (Schwerin) P. D. Sell var. glauca (Beissn.) Franco 32 Leaves more or less 2-ranked on the old twigs, the upper rank forming a V-shaped furrow along the top of the twig; cone bracts erect Pseudotsuga menziesii subsp. glaucescens var. caesia (Schwer.) Franco 33 Leaves with a petiole 33 Leaves sessile

34 36

Taxus baccata 34 Branchlets and twigs spreading 34 Branchlets and twigs hanging or erect

Taxus baccata L. forma baccata 35

35 Branchlets and twigs erect 35 Branchlets and twigs hanging

Taxus baccata forma fasciculata (Lindl.) Pilger Taxus baccata forma dovastonii (Carrière) Pilger

Sequoia / Sequoiadendron / Cryptomeria 36 Leaves dimorphic, those of side shoots linear to linear-oblong, flat, distichous Sequoia sempervirens (D. Don ex Lamb.) Endl. 36 Leaves all subulate, triangular or rhomboid in section 37 37 Leaves spirally arranged, appressed or slightly patent at apex, triangular in section; cones 30-80 mm, ovoid or oblong-ovoid Sequoiadendron giganteum (Lindl.) Buchholz 37 Leaves in 5 ranks, pointing forwards, in-curved, rhomboid in section; cones 10-25 mm, subglobose or broadly ovoid 38 38 Crown of tree rather dense with rigid twigs and shoots, side shoots at an angle of 60 degrees; leaves dark green; cones with up to 30 scales, each scale with 5 seeds. Cryptomeria japonica (L. fil.) D. Don subsp. japonica 38 Crown of tree more lax with slender drooping twigs and shoots, side shoots at an angle of 40 degrees; leaves yellowish-green; cones with less than 20 scales, each fertile scale usually with 2 seeds Cryptomeria japonica subsp. sinensis (Siebold & Zucc.) P. D. Sell 39 Many clusters with more than 8 leaves 39 Leaves 2-6 in a cluster

40 (Pinus) 48

40 Leaves deciduous; female strobili with long bracts often exceeding scales; cones not more than 4.5 cm 41 40 Leaves evergreen; female strobili with bracts minute or absent; cones more than 5 cm 43 Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Pdfs created by Chris Barron.

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Plant Crib Larix 41 Young shoots reddish to dark brown; buds resinous; bracts of young cones usually greenish with pink margins; mature cones broadly ovoid, when open nearly as wide as long and when viewed from above with a distinct rosette appearance, the bracts concealed and peduncles reddish Larix kaempferi (Lindl.) Carrière 41 Young shoots pale yellow to orange-brown; buds not resinous; bracts of young cones usually pink to red; mature cones narrowly ovoid, when open longer than broad, with at least some bracts exerted and peduncles yellow 42 42 Bracts of young cones straight; scales of cones straight or in-curved, all the bracts long-exserted Larix decidua Mill. 42 Bracts of young cones reflexed; scales of cones slightly curved outwards, the bracts short with a few exserted Larix × marschlinsii Coaz Cedrus 43 At least the low branches arching over so that the leading shoot and end of twigs although stiff appear to be drooping or hanging; leaves 25-38(-50) mm; cones 7-14 x 5-9 cm Cedrus libani subsp. deodara (Roxb. ex D. Don) P. D. Sell 43 Branches spreading or ascending so that the leading shoots and ends of twigs are patent or slightly drooping or upturned; leaves 7-35 mm; cones 3-15 x 3-8 mm 44 44 Trees broad, the branches and twigs forming Table tops giving the crown a tiered appearance; cones 9-15 x 6-7 cm Cedrus libani A. Rich. subsp. libani 44 Trees broad or narrow, branches and twigs not forming Table tops; cones 5-12 x 3-6 cm 45 45 Twigs very dense; leaves 7-15(-20) mm; cones 8-12 x 3-5 cm, long tapered from base Cedrus libani subsp. brevifolia (Hook. fil.) Meikle 45 Twigs more spreading and open; leaves 10-35 mm; cones 5-8.5 x 3-6.5 cm, broadly ellipsoid (barrelshaped) 46 46 Tree pyramidal or columnar Cedrus libani subsp. stenocoma (O. Schwarz) P. H. Davis 46 Tree broad with patent or ascending branches and twigs 47 47 Leaves shining deep green or slightly bluish Cedrus libani subsp. atlantica (Endl.) Batt. & Trab. forma atlantica (Endl.) P. D. Sell 47 Leaves bright bluish-grey or even whitish Cedrus libani subsp. atlantica forma glaucissima P. D. Sell Pinus 48 Leaves (4-)5(-6) in a cluster 48 Leaves 2 or 3 in a cluster

49 51

49 Young shoots with short reddish-brown hairs 49 Young shoots glabrous

Pinus strobus L. 50

50 Young shoots shining green; leaves 70-120 mm; cones 80-150 mm 50 Young shoots glaucous; leaves 80-200 mm; cones 150-250 mm

Pinus peuce Griseb. Pinus wallichiana A. B. Jack.

51 Leaves in groups of 3, rarely mixed with some in pairs 51 Leaves in pairs

52 53

52 Buds cylindrical; cones symmetrical, umbo with a strong erect, persistent mucro Pinus ponderosa Douglas ex P. & C. Lawson 52 Buds ovoid; cones asymmetrical, umbo with a small caducous mucro Pinus radiata D. Don

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Plant Crib 53 Buds not resinous; cone scales recurved at apex 53 Buds resinous; cone scales not recurved at apex 54 Leaves 18-25 cm; cones 14-22 cm 54 Leaves 10-20 cm; cones 9-18 cm

54 55 Pinus pinaster Aiton subsp. pinaster Pinus pinaster subsp. atlantica Villar

55 Leaves 80-160 mm 55 Leaves 30-80 mm

56 58

56 Crown pyramidal with irregular branching; leaves straight, rigid, pungent, with 2-3 rows of hypodermal cells Pinus nigra J. F. Arnold subsp. nigra 56 Crown narrow, cylindrical or ovoid-elongate; leaves often curved, more or less flexible, not or slightly pungent, with 1 or sometimes 2 rows of hypodermal cells 57 57 Branches usually more or patent and evenly spread; leaves often twisted; cones with a blunt umbo Pinus nigra subsp. laricio Maire 57 Branches usually sloping down; leaves straight; cone scales almost smooth Pinus nigra subsp. salzmannii (Dunal) Franco 58 Bark on upper part of trunk flaking to show orange blaze visible at a considerable distance; young twigs yellowish-green; leaves often more or less bluish-green; cone dull 59 58 Trunk without orange-blaze; young twigs green; leaves clear green; cone shining 60 59 Crown long remaining pyramidal, rounded only in old trees; bark thin at least above; leaves 30-45 mm; cones 25-45 mm Pinus sylvestris subsp. scotica (P. K. Schott) E. F. Warb. 59 Crown usually quickly becoming flat-topped; bark sometimes thick; leaves up to 70 mm; cones up to 60 mm Pinus sylvestris L. subsp. sylvestris (The introduced Pinus sylvestris is really of mixed origin and probably contains more than one subspecies.) 60 Leaves straight, resin canals marginal 60 Leaves twisted, resin canals median

61 62

61 Shrub up to 3 m; cones 20-50 mm, scales flat or concave-convex, not recurved and hooked Pinus mugo Turra subsp. mugo 61 Erect tree up to 25 m; cones 50-70 mm, scales recurved and hooked Pinus mugo subsp. uncinata Mill. ex Mirb. 62 Bushy tree with a dense crown up to 10 m; leaves 30-70 x 0.9-1.5 mm Pinus contorta Douglas ex Loudon subsp. contorta 62 Narrowly conical tree up to 50 m; leaves 40-80 x 1.5-2.0 mm 63 63 Buds rounded-ovoid; leaves 40-70 mm; cones 35-40 mm, remaining closed for many years Pinus contorta subsp. latifolia (Engelm.) Critchf. 63 Buds cylindrical; leaves 50-80 mm; cones 30-60 mm, opening at maturity Pinus contorta subsp. murrayana (Grev. & Balf.) Critchf.

Author

P. D. Sell, March 1988, minor updates 1998.

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Plant Crib

CRATAEGUS 1. Native taxa The main difficulty in recording Crataegus lies in distinguishing pure C. laevigata from its hybrid with C. monogyna. C. laevigata tends to flower 1-2 weeks before C. monogyna, and can then be picked out in more detail for later examination when the leaves are fully grown. The hybrid tends to overlap in flowering time. The hybrid is probably frequent throughout the range of C. laevigata (e.g. Gosler 1990), and planted extensively elsewhere. Some populations show a complete gradation between C. laevigata and C. monogyna and it has been suggested all populations in south-east England are introgressed (Byatt 1975). However, good individuals of C. laevigata can be found, typically in undisturbed woodland on heavy clay, and when showing all the C. laevigata characters below can be recorded as that species. Note that a commonly planted cultivar of C. monogyna with very dissected leaves should not be taken as the typical form of that species! All binomials for the hybrid (e.g. C. × media Bechst.) require typification before they can be used unambiguously. It is worth drawing attention to the recent studies in Ireland (Synnott 1978; Hackney 1986, Hackney & Hackney 1988) which have shown that C. laevigata occurs as a rare plant but more frequently than once supposed, and hybrids, showing every intermediate between the parents, are locally abundant. It is likely that most have been planted from imported quicks - if this pattern has been repeated elsewhere in the British Isles C. laevigata and the hybrid could be widely over-looked. Leaf shape is the best character. Specimens should include mature fruits, mature leaves selected from the short lateral spurs of shoots on the outside of the crown, and flowers if possible. Further characters are given by Byatt (1976). Sinus depth is measured along direction of veins. C. laevigata (Poir.) DC.

C. laevigata × monogyna

C. monogyna Jacq.

No. styles or fruit stones

2-3

1-2

1

Leaf shape

Shallowly 3-lobed to ± simple

M ainly 5-lobed

Laciniate, often 51obed

Intermediate

Extending at least 2/3 way to midrib

Lowest lateral Extending less than sinus depth of ½ way to midrib leaf (see above)

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Plant Crib Flower diameter

M ore than 15 mm

Variable

Up to 15 mm

Lowest lobe shape

Obtuse, broader than long; margin toothed nearly to base

Intermediate

Acute, longer than broad; margin entire or with a few teeth at apex

Habitat

Usually dense woodland on heavy soils

Hedges, edges of woods etc. on most soils

Usually in the open, on all soils

Growth habit in shade

Spreading undershrub, usually flowering well even in deep shade

Intermediate

Vertical light-seeking small tree, flowering poorly in deep shade

Crataegus laevigata

Crataegus monogyna

Crataegus laevigata × monogyna

References Bradshaw, A. D. (1971). In Hedges and local history. Pp. 20-29. Standing conference for local history. London. Byatt, J. I. (1975). Watsonia 10: 253-264. Byatt, J. I. (1976). Watsonia 11: 105-115. Gosler, A. G. (1990). Watsonia 18: 49-62. Hackney, P. (1986). Irish Naturalists’ Journal 22: 120-121. Hackney, P. & Hackney, C. R. (1988). Irish Naturalists’ Journal 22: 513-517. Jones, A. T. & Evans, P. R. (1994). Watsonia 20: 97-103. Synnott, D. M . (1978). Glasra 2: 49-55. Author

Based on pers. comms. with A. D. Bradshaw and J. I. Byatt, updated October 1997.

2. Foreign taxa A useful guide to identification of the foreign Crataegus taxa which provides much useful information additional to Stace’s New Flora is given by B. Wurzell (1992). BSBI News 61: 42-45. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib CYSTOPTERIS FRAGILIS AGGREGATE Cystopteris fragilis is a ubiquitous fern common throughout the northern hemisphere. It is cytologically complex and at least three diploid genomes have been detected in hybrids between the different races. Plants in British Isles are tetraploid or hexaploid; in mainland Europe octoploids occur. The only diploid known is in N. America Leaf architecture (degree of cutting) is very variable in both C. fragilis and C. dickieana and the form described by Sim from caves in Kincardine and subsequently brought into cultivation as a garden plant is morphologically distinct, and is that described and silhouetted here. The spores seen in that population are rugose-verrucate and thereby distinct from the spinulous spores of other C. fragilis (see Figs. a and b). The character has little taxonomic significance, however, and on a world basis, research using isoenzyme markers has shown there is little justification in regarding this spore form as anything other than a variety of C. fragilis (see Haufler et al. 1993). In Britain, C. dickieana is protected under the Wildlife and Countryside Act 1981, and recently has been found in a few new sites, in Perthshire and Easterness (Tennant 1996), and may be elsewhere, especially on limestone, mixed with more typical C. fragilis. These later finds are not typical in their cutting (they are more like C. fragilis s.s.) but they were usually found in very shady situations and have that jizz of those of the type locality: i.e., a thin, almost translucent leaf which appears distinctly paler, or almost with a glaucous tinge. The main differences are as follows: C. fragilis (L.) Bernh.: Leaf-blade mid to deep green, elliptic-lanceolate, tapering below, apex acute usually tapered, 2-3 pinnate, ultimate segments usually with acute apices and margins not overlapping. Veins usually terminating at the leaf margin in the apex of a tooth or lobe. Spores usually densely spinulose. (see Figs a and b). C. dickieana R. Sim: Leaf-blade translucent in texture, mid- to bluish-green, broadly oblong-lanceolate, tapering slightly below, apex acute but not tapered, 2-pinnate, ultimate segments obtuse to rounded, the margins often overlapping. Veins usually terminating at the leaf margin in a sinus. Spores rugose, minutely verrucate. (see Figs c and d).

Leaf shape and spores morphology of Cystopteris: (a, b) C. fragilis, (c, d) C. dickieana.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib Finely dissected leaf forms on high altitude limestone should be looked for and a voucher, preferably with mature spores, should be taken; they may turn out to be the central European alpine species, C. alpina (Lam.) Desv.) (C. regia auctt.). References

Haufler, C. H., Moran, R. C. & Windham, M. D. (1993). In Flora of North America 269-270. Oxford University Press, New York. Tennant, D. J. (1996). Watsonia 21: 135-139.

Authors

A. C. Jermy & J. M. Camus (Field Guide 1991).

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north of Mexico 1:

Plant Crib DIPHASIASTRUM ALPINUM / D. ISSLERI / D. COMPLANATUM There are two alpine clubmosses in Britain, Diphasiastrum alpinum and D. complanatum subsp. issleri (D. issleri (Rouy) Holub). The latter is the less common, being found also at lower altitudes, and during the last century on English heathland (Jermy 1989). From both morphological and ecological characters it appears intermediate between D. alpinum and D. complanatum subsp. complanatum and may well have arisen as a hybrid between those taxa. There is, however, uncertainty about the identification of the lectotype specimens of Rouy’s basionym and the name issleri is given to a different taxon in N. America (Wagner & Beitel 1993), namely to the putative hybrid between D. complanatum subsp. complanatum and D. tristachyum (Pursh) Holub.

Diphasiastrum alpinum (L.) Holub

D. complanatum L. subsp. issleri (Rouy) Jermy

D. complanatum subsp. complanatum

Habit

Main stem underground (or deep in moss or litter)

Main stem above ground (or rarely in moss or litter)

Main stem above ground (or rarely in moss or litter)

Upright shoots (Figs a, b & c)

Glaucous and resembling a cypress tree, up to 20 cm; secondary branches ± square in cross-section throughout, close together, often overlapping and compact, up to 8cm long

Distinctly yellow-green, up to 35 cm; secondary branches ± square in cross-section at apex (new growth area) becoming flat and bladelike in ageing, up to 12 cm long, usually more open than D. alpinum and fan-like

Yellow- to mid-green, up to 40 cm; secondary branches flat in crosssection and narrowly blade-like, up to 18 cm long, open and fan-like

Lateral leaves (Figs d, e & f)

Mid to lower part of the keels of opposite pairs tapering into the stem

Middle part of the keels of opposite pairs parallel, curving abruptly at the base into the stem

Middle part of the keels of opposite pairs parallel, curving abruptly at the very base into the stem

Median leaves on the lower (ventral) side (Figs d, e & f) (Best viewed on branches of the previous year's growth)

3.5–4.0 mm long, trowelshaped, with a rounded apex and an angled petiole holding it away from, but parallel to, the stem (the blade often appearing skewed in dried specimens)

3.5–4.0 mm long, narrowly lineartriangular, with an acute apex, petiole lacking

c. 1 mm, narrowly triangular with an acute apex, petiole lacking

Cones

1-2 cm long, grouped at ends of leafy branches,

1.5-2.5 cm long, borne on an erect, elongated

1.0-3.2 cm long, borne on an erect, elongated

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Plant Crib

Sporophylls

with a short, almost nonexistent peduncle bearing a few leaves intermediate in shape and texture between those of the cone and the leafy stem

peduncle bearing few ovate-elliptic, scale-like leaves

branched peduncles with only occasional scalelike leaves

Apices gradually tapering

Apices abruptly tapering

Apices abruptly tapering

Populations of D. alpina subsp. issleri in NW Scotland and the Grampians are well established and producing what appear to be good spores and the taxon can be expected on rock-strewn glacial debris now bearing open Calluna heath, or along the western seaboard on similar soils with Arctostaphylos heath.

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Plant Crib D. complanatum subsp. complanatum has not been established for the British Isles, earlier records being subsp. issleri. It could occur possibly in ancient pine woodland in NW Scotland. References Jermy, A. C. (1989). Fern Gazette 13: 257-265. Wagner W. H. & Beitel, J. M . (1993). Diphasiastrum. Pp. 28-32 in Flora North north of Mexico 2. Oxford University Press, New York. Author

A. C. Jermy 1991, revised November 1997.

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America

Plant Crib

DROSERA The three species of British and Irish sundews are readily distinguished in the field using a combination of leaf shape and position. Problems occur when the two hybrid taxa are present: D. × beleziana is probably very rare, and D. × obovata probably under-recorded. To further complicate matters, stunted or juvenile material tends towards a round leaf shape in all species and in these cases mature inflorescences must be found.

Leaf shape in (a) D. anglica, (b) D. × obovata, (c) D. rotundifolia, (d) D. × beleziana, (e) D. intermedia. 1

Petioles round to elliptic in transv erse section, glabrous; lamina (1-)2-3 × longer than wide (see note 1); inf lorescence as thick as stem, arising laterally and reaching up to twice the length of the leav es (see note 2); seeds papillate (x20 lens)

1

Petioles f lattened in transv erse section, glabrous or hairy ; inf lorescence slender, (1-)2-4(-5) × longer than the leaves, arising centrally at least at flowering; seeds reticulate, winged or undev eloped 2

2

Lamina ± round, length 0.5-1.5 × width; leav es rarely exceeding 5 cm, held against substrate or raised up to 40° f rom horizontal 3 Lamina ± obov ate to oblong, length (1-)2-6 × width; leav es usually exceeding 3.5 cm long, held at least 40° abov e horizontal, more usually nearly vertical 4 Lamina usually broader than long, leav es rarely raised abov e 30° to horizontal (except in lush Sphagnum), green to redgreen (-red); inflorescence bearing swollen capsules; seeds f usif orm, elongate-reticulate, mid-brownD. rotundifolia L. Lamina generally round or longer than broad, leav es usually raised, some abov e 30°, red-green to red-maroon (-deep maroon); inflorescence with narrow capsules; seeds undeveloped, pale brown to strawD. × beleziana E. G. Camus

D. intermedia Hayne

2 3 3

(D. intermedia × D. rotundifolia)

[Specimens with well dev eloped capsules are likely to be stunted plants of D. rotundifolia] 4

Lamina length (3-)4-6 × width in at least some leav es, leav es green with red tentacles; inf lorescence bearing swollen capsules; seeds irregular-elliptic to rhomboid, reticulate, dark brown

4

Lamina length 2-3 × width, leav es green to red-green; inf lorescence bearing narrow capsules; seeds undev eloped, linear, straw brown D. × obovata M ert. & W. D. J. Koch (D. anglica × D. rotundifolia)

D. anglica Huds. (D. longifolia L.)

NOTES

1. Lamina length is measured to the base of the lowest tentacle on the leaf. Tentacles are not included in the measurements. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 2. In D. anglica and D. rotundifolia new leaves grow in the centre of the rosette after flowering which makes old inflorescences look as if they arise laterally, resulting in some possible misidentifications if other characters are not checked. Author

A. Culham, February 1988, updated 1997.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib DRYOPTERIS 1. Dryopteris affinis / D. oreades / D. filix-mas The Male fern complex may give some difficulty due to the fact that all plants in the D. affinis complex are apomictic (called, when used with ferns, apogamous) and like flowering plants with the same breeding mechanism perpetuate populations of minor variants which often become locally common albeit restricted in distribution. The Table below will help recorders to segregate the scaly Male ferns (i.e. taxa of the D. affinis complex) and identify plants of the two sexual species, D. oreades and D. filix-mas. Dryopteris affinis (Lowe) Fraser- D. oreades Fomin Jenk.

D. filix-mas (L.) Schott

Petiole scales

Pale gold or brown to reddish gold with dark bases which remain to give a ‘peppered’ look if scale rubbed off; mixture of broad and narrow scales; apex acute or with a hair-point

Very pale grey-brown, bases not dark; all ± equal width; apex acute but not hair-pointed

Pale brown to strawcoloured, bases not dark; mixture of broad and narrow; apex hair-pointed

Pinna midrib

With a conspicuous dark mark on the underside at junction with rachis (may be faint at very apex of leaf or fade with drying)

Without a dark mark on the underside at junction with rachis (see Note 1)

Without a dark mark on the underside at junction with rachis (see Note 1)

Leaves (adult fertile plant)

Length up to 100 (-200) cm, base ± tapering or abruptly truncate; upper surface of lamina mid-green to yellow-green

Length 40-50 (-80) cm, base ± tapering; upper surface of lamina greygreen to mid-green

Length c. 35-150 cm, base ± tapering; upper surface of lamina grey-green

Pinnules

Margins lying flat (see Note 2), ranging from unlobed to having rounded to acute teeth, or with rectangular lobes bearing teeth which are prominently longer at the distal corners; apex variable square-truncate, rounded or pointed (Figs a, b); glands absent

Margins ‘crisped’ (turned up and wavy) giving a concave effect; lobes at sides blunt but teeth at rounded apex broad and divergent (Fig. c); glands present

Margins ± flat; lobes at sides ± acute; teeth at rounded apex acute, pointing towards obtuselypointed apex (Fig. d); glands usually absent

Sori

Whole pinnule fertile

Usually only proximal half of pinnule fertile

Whole pinnule fertile

Indusia of immature sori

Margins tucked well under; unicellular glands absent or very sparse

Margins tucked well under; unicellular glands frequent (best seen on margins)

Margins lying flat on the lamina surface; unicellular glands absent

Mature indusia

Either: thick, surface smooth, margins remaining well tucked-

± thick, surface granular, ‘egg-shell’ appearance,

Thin, surface smooth, margin initially

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib indusia

under as sporangia mature and lift slightly, occasionally splitting radially on maturity (Fig. e), not overlapping neighbouring indusia; persistent (mostly still present on last year's leaves) [affinis forms] Or: thinner, shrivelling and lifting to form a ± flat or wavy disc, then later rising to a ‘chanterelle’ shape (Fig. f), without radial splits, separate from neighbouring indusia; rarely still present on last year's leaves [borreri forms] (see Note 3)

becoming cinnamon coloured, usually glandular, with margins tucked under at first, developing to give a constricted ‘mob-cap’ shape (Fig. g) which usually persists until spores are shed, not overlapping neighbouring indusia; rarely found on previous year’s leaves

flattened and spreading, often overlapping neighbouring indusia, shrivelling to form a ‘chanterelle’ (Fig. h); often shed before the spores; mostly absent on previous year’s leaves

Notes to table on previous page 1. If coloration very pale check spores for sterility. 2. Morphotype ‘cambrensis’ has segments lying at an angle to plane of pinna. 3. Morphotype ‘cambrensis’ again has intermediate characters between D. affinis and D. oreades and a rather tall indusium of medium thickness but thin at the edges, maturing to form a ‘pie-crust’, sometimes splitting radially, some still present on last year’s leaves.

2. A note on the Dryopteris affinis problem Apogamous ferns contain 32 spores in a sporangium (instead of the usual 64 found in sexual species), with each spore (and resulting prothalli and gametes when formed) containing the same genetical material as the parent fern plant (sporophyte) producing it. Furthermore a new generation of sporophyte is produced directly from the prothallus without the usual fusion of gametes, a process that produces a new generation of clones (identical individuals). Any minor mutation will be passed on to future generations by the same process and thereby form a new population, morphologically distinct although with a very limited distribution (Manton 1950).

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Plant Crib The ancestry of D. affinis agg. is complicated and thought to involve an unknown species and two sexual diploids, D. oreades and the non-British D. caucasica (A. Braun) Fraser-Jenk. The common Male Fern, D. filix-mas, which has evolved through hybridisation between the latter two species, hybridises freely with all forms of D. affinis (see below) and through this process can introduce the genomes (and thereby characters) of those species into the affinis complex. For the reasons stated below, the Dryopteris affinis complex shows a wide range of morphologies of leaf shape, teeth and lobes of pinna segments, indusium shape and texture and degrees of scaliness. All morphotypes have indusia with the margin tucked under to enclose the developing sporangia in the youngest stages (as has D. oreades). As the sporangia mature, so do the indusia – in various and distinctive ways characteristic of the different morphotypes. But not all sori, even on the same pinna segment, develop at the same rate and this is reflected in the variety of form of the indusia seen on any one pinna or leaf. Thickness, especially of the margin, and texture are also important features of the indusium in this group of ferns. The table below distinguishes these apogamous plants from the sexual species with which they can be confused. Such a situation is a challenge to field botanists, and those who want to study the variation seen in their vice-county in some detail may find published work on the group lacking in the taxonomic clarity needed for precise identification. Even those who have worked on the group for some time find some specimens, albeit often distinct at the individual level and possibly, occasionally, at the population level also, that are almost impossible to assign to any taxonomic unit (conventional or otherwise) presently recognised. We therefore recommend that for the Atlas 2000 database records of the aggregate species only are submitted. However, work continues on the group and more field data and specimens are needed and the authors of this note are keen to see as much material as possible. A detailed appraisal of the D. affinis complex thus gained over the next three years will be published by the British Pteridological Society in a revision of the Fern Atlas. Some botanists have already embarked on regional or county surveys (e.g. Cornwall, Cards, Cumbria, NE Yorks, Arran) that have proved of considerable interest, and these and any further collaborators will be fully acknowledged. As a background to this study we provide some introductory text below. Whilst recording for Atlas 2000 we strongly recommend that those undertaking fieldwork make pressed vouchers for later determination by the undersigned, or send fresh material to ACP as below. Material should be fertile, showing black but undehisced sporangia and firm indusia and show a complete leaf (including petiole) if possible. Fresh material to be sent to Anthony Pigott at Kersey’s Farm, Mendlesham, Stowmarket, Suffolk IP14 5RB, by first class post and marked ‘Affinis’. Dried vouchers should be sent to BPS Affinis Watch, c/o Botany Department, The Natural History Museum, Cromwell Road, London SW7 5BD. A note on ‘hybrids’ The prothalli of any genotype within the complex, whilst unable to form viable egg-cells, can nevertheless form functional male gametes which can cross-fertilise other sexual species (e.g. D. filix-mas, D. oreades) and hybrids can thus be formed. Early generations of such hybrids will show a very high proportion of abortive spores but some sporangia will contain some well-formed spores which will germinate and produce, apogamously, further plants exhibiting hybrid characters. When D. filix-mas is the sexual parent, the resulting hybrids are called D. × complexa Fraser-Jenk. (D. × tavelii auctt.). The plants are usually more like D. filix-mas but always have a black spot (sometimes faint) at the pinna-rachis junction and have a high percentage of spore abortion. There is evidence (K. Trewren, pers. comm.) that the percentage of abortions in populations of such plants can vary from 35% to 75% and it is a possibility that each successive generation has fewer abortive spores than the last. Furthermore, they occur usually as solitary plants, whereas morphotypes (i.e. established apogamous forms of D. affinis that may look similar (and often do), occur usually as sizeable populations. Fraser-Jenkins subsequently (in Derrick et al. 1987) described three nothosubspecies depending on which subspecies of D. affinis (see below) is involved in the crossing. Morphology is significant but the chromosome number is the only way to check such origins: those involving subspp. borreri (nothosubspecies critica Fraser-Jenk.) and cambrensis (nothosubspecies contorta Fraser-Jenk.) will be pentaploid (5x); and that with subsp. affinis, tetraploid (4x). Fraser Jenkins, an undisputed expert in the group, gave (loc. cit., xii) a detailed description of nothosubspecies contorta in which he presumed the plant to be pentaploid (because of the morphology and the parentage proposed). When the type specimen was later counted (M. Gibby, pers. comm.) it was found to be tetraploid. As these nothosubspecies are so difficult to identify, D. × complexa should not be recorded to the nothosubspecies level. However, vouchers should be made of any suspected plants which have 60% or more abortive spores. Hybrids with D. oreades are more difficult to detect but will similarly have a high percentage of abortive spores. They have so far not been specifically named and given binomials as hybrids but it is possible that D. affinis subspecies/morphotype cambrensis (a triploid) is the result of D. oreades crossing with the diploid subspecies/morphotype affinis or something similar. Whatever their origins, such specimens will have sufficient characters of D. affinis to place and record them within that complex. However, any with a high proportion of abortive spores should be collected for further determination. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib A practical approach to the nomenclature of the Dryopteris affinis complex Formal botanical names have been given to many units of the variation seen in this complex, including plants with intermediate morphology with related sexual species, but the usefulness of naming within a formal taxonomic framework is questionable until detailed analysis has been carried out. Some British floristic accounts (e.g. CTM 1987; Page,1997, and Stace, New Flora) have divided the aggregate into three subspecies: affinis, borreri (Newman) Fraser-Jenk. and cambrensis Fraser-Jenk., based on Fraser-Jenkins (1980 1996) with varied attempts at definitive descriptions. Beitel & Buck (1988) discussed the use of subspecies rank for these taxa and recommend specific rank to reflect the biological situation. The present authors prefer to have an open mind as to the affinities of the wider range of morphological/taxonomic ‘units’ for the present exercise and prefer the term ‘morphotypes’, a term without rank not governed by the Code of Botanical Nomenclature thereby nullifying the problems of potential nomenclatural changes. This terminology also avoids the necessity of showing relationships within a hierachy of formal names. The final presentation on the distribution and ecology of the ‘morphotypes’ studied will be put eventually into a formal nomenclatural context. More detailed descriptions of these morphotypes, based on work done by A. C. Pigott (unpublished), were published in Jermy & Camus Field Guide where five of the most commonly seen and easily distinguished types were described. This approach has been elaborated by Pigott (1997) who has described in tabular format nine morphotypes within the complex. References 15-16.

Beitel, J. & Buck, W. R. (1988). Fiddlehead Forum (Bull. Amer. Fern Society) 15(2): Derrick, L. M., Jermy, A. C. Jermy & Paul, A. M. (1987). Somerfeltia 6: xii-xiii. Fraser-Jenkins, C. R. (1980). Willdenowia 10: 107-115. Fraser-Jenkins, C. R. (1996). Fern Gazette 15: 77-81. Manton, I. (1950). Problems of cytology and evolution in the Pteridophyta. Cambridge University Press, Cambridge. Pigott, A. (1997). Affinis Watch, April 1997: 1-4. (Also on WWW http://www.btinternet.com/pigott/anthony.htm.)

Authors

A. C. Jermy, A. C. Pigott & J. W. Merryweather, January 1998.

3. Dryopteris aemula / D. dilatata Once known these two species are rarely confused but the following may help: D. aemula (Aiton) Kuntze: Leaves mid apple-green, highly glandular on lamina and veins (smelling of hay when dried), remaining green through winter, lamina margins turned up (even from very young stage), giving a characteristic appearance which pteridologists term ‘crispy’; petiole purple-red on all faces, pruinose; scales pale brown, concolorous, narrowly triangular; rhizome erect, the growing point flat. D. dilatata (Hoffm.) A. Gray: Leaves, deep, almost bluish-green, not glandular except on axes when young, mostly dying down in winter, lamina margins turning down; petiole orange-brown on abaxial side, paler often greening on inner (abaxial) face; scales pale, with wide dark brown central stripe, broadly triangular-ovate; rhizome erect, the growing point domed.

4. Dryopteris carthusiana / D. dilatata / D. expansa In their typical forms these three species present no problem but shade forms of D. dilatata can have the flat leaf blade of the other two species and then pinnule cutting and spore sculpturing may be used to help identification. Both D. dilatata and D. expansa can spread by short (up to 40 cm long) stolons which end in a rosette of leaves bearing on their petioles pale concolorous scales more typical of D. carthusiana.. Young leaves of all three species are triangular in outline and should not be confused with D. aemula, the leaves of which are of a fresh yellow-green and have their margins upturned. Hybrids between all three species can occur and are best detected by examination of sporangia that do not dehisce and contain abortive spores. That between D. carthusiana and D. dilatata (D. × deweveri (J. T. Jansen) Wacht.), frequent where both parents grow together, has the leaf cutting of D. carthusiana but an erect rhizome, and the scales are orange-tinged with only a Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib faintly darker centre. That between D. dilatata and D. expansa (D. × ambroseae Fraser-Jenk. & Jermy) is also usually present where the two parents grow together but is more difficult to detect. Its more yellow-green, erect and more finely cut leaves may suggest it but abortive spores will be the best confirmation. D. carthusiana × expansa (D. × sarvelae Fraser-Jenk. & Jermy) is a rare hybrid found in west Scotland (V.c. 97 & 101) where in one site it forms a large distinct population. It is characterised by a mat, almost glaucous tinge to the erect leaf. If growing with D. expansa it is seen to die back slightly earlier (i.e. it is less frost-resistant). D. carthusiana (Vill.) H.P. Fuchs

D. dilatata

D. expansa (C. Presl) Fraser-Jenk. & Jermy

Plant with few, erect leaves on a creeping, occasionally branched rhizome, not forming a ‘shuttlecock’; growing point flat, with 4 bright green croziers (upper, lower, and two at side); leaves dying rapidly after frost

Plant with leaves arching and clustered in a ‘shuttlecock’ on a short, ± erect rhizome (see Note 1); growing point domed, young croziers usually more than 4, radially spaced, colourless; leaves staying green through the early part of winter

Plant with leaves only slightly arching and forming a sparse ‘shuttlecock’ from a ± erect rhizome (see Note 1); growing point domed, young croziers as in D. dilatata; leaves soon dying down in winter except in very sheltered sites

Leaves Narrowly lanceolate, pale (see note 2) to yellowish-green

Triangular-ovate, dark bluish-green

Triangular-ovate, mid- to pale green

Petiole scales

Sparse, almost colourless when on young croziers, becoming pale brown with ageing, without a central dark stripe, appressed to petiole, broadly lanceolate, hair-pointed

Dense, at least near base, pale brown with a broad dark central stripe even when on young croziers (but see Note 1), usually flat, appressed to petiole, broadly ovate-deltate apex long acuminate

Dense, at least near base, typically uniform brownginger, even when on young croziers, occasionally with a darker central stripe (but see Note 1), often patent or bullate, broadly ovate-deltate, with apex often abruptly acuminate

Pinnules

With edges flat in plane of lamina, segment margins with conspicuous long, incurving, spinulose-tipped teeth

With margins turning under, segments linearoblong, not cut to midrib, with short spinulose-tipped teeth

With edges flat in plane of lamina, segments ± oval, , cut ± to midrib (giving leaf a lacy appearance), with short spinulose-tipped teeth

Spore sculpturing

Rugose with wings less well formed and scattered, sometimes spiny, tubercles

Winged, with ± dense spines or tubercles, darker than those of D. expansa (see Note 3 below)

Winged, with sparse spines or tubercules, paler than those of D. dilatata (see Note 3)

Habit

Notes

1. Some plants have stolons originating from leaf axils which creep until 20-30 cm from parent plant when they become erect. They should not be confused with the thick rhizomes of D. carthusiana. 2. Leaves on stolons may be distinctly triangular. 3. The best way to know this comparative colour is to mount spores of both species (having confirmed identity on other characters) on the same slide. Authors

A. C. Jermy & M . Gibby, January 1998. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

ELEOCHARIS 1. Eleocharis austriaca E. austriaca Hayek is known at a few sites in N England and S Scotland, and thorough searching may well lead to its discovery elsewhere. It usually grows on a gravel substrate with some silt deposition where there is slow water movement and some protection from spates, typically in ox-bow and other pools, runnels, and springs beside upland rivers, less often along the banks of the main river. It has also been found in pools in an old quarry (Ribblesdale) and an old gravel pit (Wharfedale). It is an early colonist in such sites, but tends to weaken with increased deposition of silt, sometimes giving way to E. palustris. A few sites are known in the ‘middle’ reaches of rivers, down to c. 60 m altitude. Observations of flower/fruit characteristics are essential for accurate identification: i) Stigmas 2 as in E. palustris, shape/size of lowest glume and upper leaf-sheath as in E. palustris. ii) Style base much smaller, c. 1/10 of the bulk of the nut, not markedly constricted at the base (in E. palustris style base c. 1/4 or more of bulk of nut, and markedly constricted at the base). iii) Bristles around base of nut usually 5 (in E. palustris usually 4). Do not confuse these bristles with the (three) anther filaments: bristles carry minute down-pointing hooks, and grow from a tiny collar of tissue at the base (see figures). The filaments (not shown in the figures) are hair-like, smooth, and longer than the bristles; they arise between the nut and the bristle-collar. They persist after the loss of the anthers, but are eventually shed.

Nuts and spikes (a) E. palustris, (b) E. austriaca (del. FJR)

Apart from the fruiting characters, E. austriaca differs from E. palustris in: iv) The absence or poor development of reddish-purple colour at the base of the stem. v) The spikes characteristically compact and narrowly-conical and pointed, in contrast with the usually cylindrical spikes of E. palustris (though conical forms are known in E. palustris). vi) Stems somewhat inflated and brittle, with a circular cross-section. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib 2. Eleocharis uniglumis E. uniglumis (Link) Schult. sometimes presents difficulties. A useful character to pick it out from all other species is that the heads often point strongly sideways. The typical plant with thin stems in saltmarshes is easy to identify, especially if the stem is well-developed to show the single glume encircling the base of the spikelet, the fertile second glume, and the punctate pattern of the ripe nut. However, there are puzzling inland populations in England and coastal populations in Scotland of plants intermediate between E. palustris and E. uniglumis (Wigginton & Graham 1981). Some of these have been shown to have intermediate chromosome numbers and are probably of hybrid origin. Further-more, plants with a high polyploid number (2n = c. 90) may occur in mixed populations with the ordinary E. uniglumis (2n = 46).

3. Eleocharis acicularis E. acicularis (L.) Roem. & Schult. is usually sterile when submerged, and the stems are not always clearly 4-angled (in section they are 3-chambered). Submerged plants are often overlooked, and are often most easily found when exposed during hot summers when water levels are low. Mats of bright green, very fine leaves should be investigated. It is probably declining but may be under-recorded (Scarce Plants). References Roberts, F. J. (1977). BSBI News 15: 16-17 Walters, S. M. (1963). Watsonia 5: 329-335 Authors

F. J. Roberts, S. M. Walters & T. C. G. Rich, January 1998, and M. J. Wigginton & G. G. Graham (1981).

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib

ELODEA / LAGAROSIPHION / EGERIA DENSA / HYDRILLA

Assuming most botanists know Elodea, the following jizz characters may help pick up the other taxa in the field, even under water. Lagarosiphon is readily picked out as having much chunkier shoot apices (c. 2 × normal Elodea size); the spirally arranged leaves are best seen away from the short apex where they are too densely crowded. It is now common in many ponds in southern Britain and is surprisingly frequently confused with Elodea, though they are easily distinguished. Very robust (c. 3 × normal Elodea size) plants with leaves in whorls of 4-5 may be the rare introduction Egeria densa. Slender, bluishgreen, semi-translucent plants should be checked to see if they are the very rare Hydrilla verticillata. Details of their distributions are given in Simpson (1984) and Aquatic Plants. The taxa are keyed out below. Elodea canadensis and E. nuttallii are both phenotypically plastic (Simpson 1988); difficult material should be sent to a referee. Nodal scales are small ± membranous scales in the axils of the leaves. 1 1

Leav es spirally arranged along stem, of ten densely crowded at shoot apices, leav es usually strongly recurv ed Lagarosiphon major (Ridl.) M oss Leav es in whorls of 3-5, the whorls crowded or lax, leaves recurved or not 2

2 2

Leav es mostly in whorls of 3(-5) (common) Leav es mostly in whorls of 4-5 (very rare)

3

Leav es linear-oblong, oblong-lanceolate, oblong, oblong-ov ate or ov ate, rarely linear-lanceolate; leaf apices broadly acute or obtuse, rarely narrowly acute, (0.7-)0.8-2.3 mm wide c. 0.5 mm below the apex (Figs. a-e) Elodea canadensis

(Elodea) 3 5

M ichx. 3

Leav es linear or linear-lanceolate; leaf apices narrowly acute or acuminate, 0.2-0.7(-0.8) mm wide c. 0.5 mm below the apex (Figs. f -i) 4

4

At least some leav es strongly recurv ed; leaf lamina of ten strongly twisted; leaf margin teeth 60-90 (-100) µm long; adv entitious root-tips (in liv ing material) white or grey green; sepals of f emale f lowers 1.6-2.5 mm long

4

Leav es nev er strongly recurv ed; leaf lamina rarely strongly twisted; leaf margin teeth (80-)110-140 µm long; adventitious root-tips (in living material) red; sepals of female f lowers 3.1-4.3 mm long (very rare)Elodea callitrichoides (Rich.)

Elodea nuttallii (Planch.) H. St. John Casp. (E. ernstiae H. St. John) 5 5

Hydrilla verticillata (L. f.) Royle Egeria densa Planch.

Nodal scales f ringed; plant slender Nodal scales entire; plant robust

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

a

b

c

d

e

f

g

h

i

Outlines of leaves of Elodea species (a-e) E. canadensis, (f-g) E. nuttallii, (h-i) E. callitrichoides.

j

k

l

m

n

o

Leaf posture types. (j) spreading, (k) patent, (l) erecto-patent, (m) arcurate-deflexed, (n) slightly deflexed c. 2-4 mm from the leaf base, (o) strongly recurved, with leaf bases often touching or overlapping the stem. E. canadensis E. nuttallii E. callitrichoides

j, k, l, m j, k, l, m, n, o j, k, l, m, n

References Simpson, D. A. (1984). Watsonia 15: 1-9. Simpson, D. A. (1986). Watsonia 16: 1-14. Simpson, D. A. (1988). Watsonia 17: 121-132.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

EMPETRUM NIGRUM A useful tip for spotting E. nigrum L. subsp. hermaphroditum (Hagerup) Böcher quickly in the field is to look for plants with abundant fruit. Then, examine the back of the fruit and look for the remains of the three stamens which often persist between the perianth and the fruit. The stamens may persist intact with the anthers attached, but often the anthers are lost leaving slender, white filaments c. 2-3 times as long as the perianth segment. These can easily be seen with a lens or by eye. Reduced, sterile filaments without anthers are present in subsp. nigrum fruits, but these are brown, short and hidden under the calyx segments and can really only be seen if you are looking specially for them under a microscope.

When fruit are absent or fruit determinations inconclusive, it is possible to carefully dissect, under a microscope, next years’ flower buds (present from mid-summer onwards). Buds of subsp. hermaphroditum have both ovary and anthers present. Buds of subsp. nigrum either have only an ovary, or only stamens (the latter more easily visible; reduced filaments (cf. above) are virtually impossible to see at this stage, even under a microscope). Similarly, flowers can also be examined in spring and early summer. Note that the dioecious versus hermaphrodite flower character is not absolute; hermaphrodite subsp. nigrum has been reported in Durham and elsewhere (Blackburn 1938), and monoecious (i.e. different sex flowers on different branches of the same plant) subsp. hermaphroditum reported in Sweden (Danielsson 1988). It is therefore best to check several plants or flowers. Subsp. hermaphroditum tends to be a more erect plant with denser shoots, and is characteristic of broken, rocky, north-facing ground towards it southern limit in Britain though it occurs at sea level in the north. Subsp. nigrum tends to be more prostrate with more lax shoots, often also on peat. Stace’s New Flora and Danielsson (1988) list other characters and should be consulted for non-typical plants. Altitude ranges overlap. References Blackburn, K. B. (1938). Journal of Botany 76: 306-307. Danielsson, B. (1988). Svensk Bot. Tidskr. 82: 118-124. Authors

T. C. G. Rich, R. W. M . Corner & G. A. Swan, 1992. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

EPIPACTIS There is a long-standing confusion between a rostellum and its viscidium. All Epipactis Zinn species have, to some extent, a rostellar projection to the stigma (Fig. a). In allogamous (cross-pollinated) species, the rostellum secretes a white sticky cap, the viscidium. Shortly after the flower opens, the two pollinia drop from the anther into grooves (clinandria) in which position they adhere apically to the viscidium. The pollinia and viscidium together form the pollination unit. Hence cross-pollination can be ascertained by the presence of a viscidium, which when touched with, for example, the point of a pencil will draw out the pollinia. It will also be indicated by the absence of pollinia from the majority of older flowers. For a full description of cross-pollination, see Richards (1986). In autogamous (self-fertilised) species the viscidium is not visible (except sometimes in the uppermost newly-opened flower where it quickly fades and disappears) and the pollinia remain, eventually crumbling to fertilise the stigma of the same flower.

Flower with perianth segments removed to show structure

The following key to E. helleborine and British autogamous species of Epipactis is modified from Richards & Porter (1982), who also give a Table of comparative characters:1

1

2 2

3

Leav es ty pically dark green but y ellowish if stressed, rather rigid, strongly ribbed, rough, the bottom-most usually wider than long, concav e, rounded at apex; v iscidium remaining in the open f lower (unless remov ed by an insect) with the pollinia intact E. helleborine (L.) Crantz Leav es ty pically y ellowish-green to green, f laccid, smooth, the bottom-most usually longer than wide, ± f lat, subacute; viscidium usually absent and pollinia disintegrating in situ 2 Upper rhachis glabrous or v ery sparsely pubescent with short, stout 'prickle' hairs; leav es green , short, patent, scarcely exceeding internodes; flowers green E. phyllanthes G. E. Sm. agg. Upper rhachis shortly but rather densely sof t-pubescent; leav es y ellowish-green, suberect, exceeding internodes; flowers pinkish to yellowish 3 Rostellum long, of ten ± equalling anther, acute with two acute basal bosses f orming a tricornute stigma; clinandrium deep with pollinia sunk into it and scarcely v isible; petals mostly rose, or y ellow-green in shade; f lowers box-shaped, ovary ± glabrous (Northumberland and Scotland)

E. youngiana A. J. Richards & A. F. Porter

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Plant Crib 3

Rostellum shorter, not exceeding 3/4 length of anther; basal bosses to stigma absent or short and inconspicuous; clinandrium shallow exposing the pollinia; sepals and petals y ellowish green; f lowers saucer-shaped; ov ary usually pubescent (E. leptochila (Godfery) Godfery) 4

4 4

Epichile longer than wide, narrow, acute, usually patent Epichile wider than long, acuminate, reflexed E. leptochila

E. leptochila var. leptochila var. dunensis T. & T. A. Stephenson

It is not currently thought worthwhile to separate E. phyllanthes var. phyllanthes, var. vectensis and var. pendula as there are so many mixed populations and intermediates. E. phyllanthes is protected in Ireland under both of the Wildlife Act 1976 and the Wildlife (NI) Order 1985 and must not be collected. E. youngiana is very distinct amongst the autogamous species. It is easily confused with some forms of E. helleborine, but the yellowish, smooth, unribbed leaves, pinkish (not ‘dirty’) flowers and floral characters will distinguish it. E. youngiana is protected under the Wildlife and Countryside Act 1981 and must not be collected. Inland populations in Northumberland, Durham, N Yorkshire and Lincolnshire raise serious questions as to the status of E. dunensis as E. dunensis-like plants grade with E. leptochila-like plants in E. leptochila-like inland habitats. It is now probably best treated as E. leptochila var. dunensis. The following notes apply to taxa keyed out in Richards & Porter (1982), but not above:i) E. confusa is closely related to E. phyllanthes and is probably best treated as a variety of it. Plants probably best referred to this occur in 3 localities in Yorkshire and Northumberland although they have relatively large flowers and their identity is not certain. ii) E. muelleri Godfery is very dubiously distinct from E. leptochila var. dunensis (it may eventually merit recognition as another variety of E. leptochila). There are no certain British records, although one population in Sussex may be referred to this. Note that E. muelleri is the prior epithet at specific rank, and replaces E. leptochila if the unification is made. Two other taxa from Kenfig (V.c. 41) are also worth noting, though their precise status has yet to be resolved: E. cambrensis C. A. Thomas is a distinctive autogamous plant which may be best treated as a variety of E. leptochila; it differs from E. leptochila var. dunensis by having reddish flowers and a tricornute stigma. The E. helleborine at Kenfig is very remarkable in being a very stout, yellowish plant with crowded inflorescences and yellow or reddish flowers, almost of E. atrorubens colour. It may be identical with similar plants in Europe known as E. helleborine subsp. neerlandica (Verm.) Buttler. References Richards, A. J. & Porter, A. F. (1982). Watsonia 14: 121-128. Richards, A. J. (1986). Watsonia 16: 180-182. Author

A. J. Richards, January 1988, updated November 1997.

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Plant Crib EQUISETUM Equisetum is divided into two distinct subgenera (which by some European botanists are accepted at generic rank, with good reason): Equisetum and Hippochaete (Milde) Baker. Hybrids are formed between most species but not between species in different subgenera. Normally hybrids are found where the two putative parents grow together but E. × moorei is often found well beyond the present range of E. ramosissimum. Page & Barker (1985) discuss the biology and geography of hybrids in Equisetum. Page (1997) describes in detail the morphology of Equisetum seen in the British Isles. Hybrids so far found in the British Isles are given below.

1. Equisetum hyemale / E. ramosissimum / E. × moorei E. ramosissimum is protected under the Wildlife and Countryside Act 1981. It is generally accepted that the Lincolnshire population of that species was introduced. However, that in Somerset was misidentified for many years (FitzGerald & Jermy 1987) and it is possible that the species may turn up elsewhere. E.× moorei, the putative hybrid between E. ramosissimum and E. hyemale, is spasmodic in its appearance throughout Europe and is recorded so far only from V.c. H20. Any stand of an Equisetum that might pass as E. hyemale but which has no or few cones should be looked at more closely.

T.S. of stem internodes: (a) Equisetum hyemale, (b) E. × moorei, (c) E. ramosissimum. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib E. hyemale L.

E. × moorei Newman

E. ramosissimum Desf.

Stem

Deep green, erect, unbranched, with 10-30 ridges; stem feels firm and rough, hollow 2/3 - 3/4 diameter; winter-green

Deep green, erect, unbranched, with c. 20 ridges; stem feels firm hollow 2/3 diameter; dies down in winter unless in warm hollow

Green, often ± glaucous, tending to lie prostrate if not held up, with 10-20 distinct ridges, irregularly branched, slightly rough; stem feels soft, hollow 1/2 2/3 diameter. dies down in winter unless in warm hollow

Internodes

Become inflated so that stem seems narrowed above and below sheaths

Not or only slightly inflated

Not inflated

Sheath teeth

Quickly lost as stem expands, leaving a ‘pagoda’ of whorls of teeth at stem apex and a dark, crenulated upper margin to sheath

Black, attenuated from triangular base c. 1 mm, not lost until stem fully expanded then leaving a slightly crenulated margin

Black, pointed, persistent, up to 5 mm, with scarious margin very narrow or lacking,

2. Equisetum hyemale / E. variegatum / E. × trachyodon The hybrid Equisetum × trachyodon (recorded for V.c. 58, 67, 70, 88, 90) is more like a robust form of E. variegatum. The nodal sheath teeth show the most useful characters. Equisetum hyemale L.

E. × trachyodon A. Braun

E. variegatum Schleich. ex F. Weber & D. Mohr.

Cone

Not apiculate but sharply pointed, 7-15 mm long, partly concealed by teeth of uppermost sheath

Apiculate at apex, 4-5 mm long, usually remaining half within the uppermost sheath

Apiculate at apex, 5-7 mm long

Stem

Deep green, erect, unbranched, less than 12 mm wide, with 10-30 ridges; stem feels soft, hollow 2/3 – 3/4 diameter of stem; wintergreen.

Deep green; erect or becoming procumbent, sometimes branched on previous year’s stems and then very much like E. variegatum, 8-13 acutely bi-angled ridges, hollow 1/2 diameter of stem; winter-green

Deep to mid-green, usually prostrate or ascending, occasionally erect, with 68 bi-angular ridges, hollow c. 1/3 diameter of stem; winter-green

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Plant Crib Continued

Equisetum hyemale

E. × trachyodon

E. variegatum

Internodes

Becoming inflated so that stem seems narrowed above and below sheaths; stomata not obvious

Not or only slightly inflated; stomata just visible as in E. variegatum

Not inflated; stomata visible as a single row of white dots either side of each trough between stem ridges

Sheath

Green at first, becoming pinkish-grey in middle, with a black band at base that broadens with age

Pale green or ash grey with narrow black band near top, becoming almost totally black

Black band develops at base of sheath teeth; nodes and internodes may be orange-tinted

Sheath teeth

Soon lost as stem expands, leaving a dark, crenelated upper margin to sheath and a ‘pagoda’ of whorls of teeth at stem apex.

Finely attenuate apex, black, with scarious margin of varying width below, eventually lost during winter

Broadly triangular, with a broad, white, scarious margin and a dark mid-line ending in a dark hair-point which is soon lost from the otherwise persistent tooth.

3. Equisetum arvense / E. palustre / E. × rothmaleri In high altitude flushes and micaceous mires small forms of E. arvense which are rarely branched can be mistaken for E. palustre but their sheath teeth are characteristic. Similarly unbranched and very slender forms of E. palustre grow in similar base-rich mires and can, in turn, be confused with E. variegatum. Presence of a cone will dispel any doubts, that of E. variegatum being apiculate. Also compare Tables above and on next page. The hybrid between Equisetum arvense and E. palustre (E. × rothmaleri) is rarely detected (V.c. 20, ?52, ?82, 104) but should be looked for where the two parents grow near each other, which is often. Those found have the jizz of E. arvense early in the year but soon develop that distinct green of E. palustre and these two stages can be found growing together. On closer examination it will be seen that it is not completely identical with E. palustre.

T.S. of stem internodes: (a) Equisetum arvense, (b) E. × rothmaleri, (c) E. palustre. (Partly after Page, 1997, with the permission of Cambridge University Press.) Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Equisetum arvense L.

E. × rothmaleri C. N. Page

E. palustre L.

Cone

Ovoid when young, elongating on ageing, 1040 mm, on colourless stems in spring

Ovoid-cylindrical, 4-9 mm, on green shoots in summer

Cylindrical, 15-25 mm, on green shoots in summer

Sterile stem

Robust erect pale stems with 8-20 ridges, smooth, stem feels firm (it resists a gentle squeeze), hollow less than 1/2 – 1/3 stem diameter; stomata not obvious with × 10 lens; branches usually spreading

General appearance when first emerging in Spring somewhat robust and often pale pinkish, with 6-12 ridges, hollow 1/2-1/4 diameter of stem; stomata not obvious

Very smooth, with 5-9 ridges; stem feels very firm, hollow less than 1/4 diameter, stomata visible with × 10 lens as white dots scattered in each trough between stem ridges; branches ascending

Sheath teeth

With black tips, no or very narrow scarious margin

With black tips, with narrow scarious margin

With a conspicuous broad, white, scarious margin surrounding the central black triangle

Branch internode and ocreolae (small scales) at junction with main stem.

4-angled in TS, 1-2 mm wide; lowest internode equal to or longer than adjacent stem sheath, with pale ocreolae

4-6-angled in TS, c. 1 mm wide; lowest branch internode about as long as or slightly longer than adjacent stem sheath, with dark ocreolae

4-6-angled in TS, c. 1 mm wide; lowest branch internode much shorter than adjacent stem sheath, with black ocreolae

Branch teeth

Usually green throughout, spreading away from branch axis, free part 1-2 mm long

Black-tipped but spreading away from branch axis

Usually blackish-tipped, with a scarious margin, clasping branch axis

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Plant Crib 4. Equisetum pratense / E. sylvaticum / E. × mildeanum Equisetum pratense and E. sylvaticum frequently grow together in upland base-rich mires and adjacent grassland. Their hybrid (E. × mildeanum) has been recorded in V.c. 88, 89 and 90, and could be elsewhere within the sympatric range. E. pratense Ehrh.

E. × mildeanum Rothm.

E. sylvaticum L.

Sterile shoots

10-30 cm × 1-3 mm, pale, ± glaucous green; outline blunt-topped or rounded, terminal segment of main stem nodding when fully expanded; branches simple, slender, usually curved down, without secondary branches

10-50 cm × 2-6 mm, very similar to E. pratense in general appearance and often with a ± compressed appearance; apex somewhat tapered but often nodding and branches slender, with only occasional secondary branches

10-50 cm (occasionally larger in lush sites) × 3-6 mm, grass-green, outline abruptly tapered to a short, often nodding spire; branches usually bearing 5 or more secondary branches, gracefully drooping

Stem

With 8-20 ridges, very rough, feels very firm, hollow c. 1/2 diameter of stem

With 8-15 ridges, smooth to slightly rough, feels firm, hollow c. 1/2 diameter of stem

With 10-18 ridges, each main ridge topped by two small ridges of silica, smooth to fairly rough, feels firm, hollow 1/4 - 1/3 diameter of stem

Sheath teeth

With a black centre and a conspicuous broad, white, scarious margin, teeth not adhering together

As E. pratense but some teeth adhering together

With a dark central stripe and a very broad, russetbrown, scarious margin, teeth adhering at margins into groups of 2 or 3

Branch internode and ocreolae

3-angled in TS, 0.5-1 mm wide; lowest branch internode shorter than adjacent stem sheath at lower nodes, but longer at upper nodes; ocreolae pale

3-angled in TS, c. 1 mm wide, lowest branch internode always longer than adjacent sheath; ocreolae pale

3(-4)-angled in TS, 0.5-0.6 mm wide; lowest branch internode always longer than adjacent sheath; ocreolae dark

Branch teeth

Often brown tipped, free part 0.5 mm, appressed to branch axis

Green, c. 1 mm long, slightly spreading, acuminate

Green, c. 1 mm long, slightly spreading, slender, acutely pointed

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Plant Crib 5. Equisetum palustre / E. × litorale / E. × dycei Equisetum fluviatile L. hybridises with E. arvense (to form E. × litorale) and E. palustre (to form E. × dycei). Both hybrids can be confused and it is possible that some early records for E. ω litorale may have been E. × dycei and possibly branched forms of E. fluviatile. Whilst both E. × dycei and E. fluviatile can be found on the bare shores of more oligotrophic lakes, the latter has a very large central hollow (over 3/4 of stem width). The former, probably more common than present records show, has a characteristic procumbent base to its sterile stem; it is also rarely forms cones. E. × litorale on the other hand, is more frequently found on banks and near ditches. It can be very similar to E. arvense but does have a larger cavity in its stem such that a gentle squeeze will detect it. When the same pressure is put on E. arvense the stem will resist and feel firm. If you break the stem (and gently pull it apart) E. arvense will retain the inner cortical cylinder within, whereas E.× litorale will snap completely leaving a ragged edged break (Merryweather 1992). For characters of E. arvense see page 11. E. palustre L.

E. × litorale Kuhlew. ex Rupr.

E. × dycei C. N. Page

Cone

Cones usually present in summer; blunt-tipped, slightly tapered

Rarely produced; terminal on main stem in summer, barrel-shaped, c.8-12 mm, remaining tightly closed

Rarely formed; terminal on main stem in summer, barrel-shaped, 10-15 mm, remaining tightly closed

Stem

Dull to fresh green, very smooth, with 5-9 ridges; stem hollow less than 1/4 diameter, very firm; branches regularly whorled at most nodes; stomata visible (×10 lens) as white dots scattered in each trough between stem ridges

Dull grey-green, c. 9 ridges, hollow 1/3-1/2 diameter, branches irregularly clustered towards prostrate base, upper half unbranched, curved and flagellate (whiplike); stomata not conspicuous

Bright green often with slight orange tinge around nodes, 9-12 ridges, hollow c.1/4 diameter, yields slightly to gentle pressure between finger and thumb; branches regularly whorled at most nodes; stomata not conspicuous

Sheath teeth

With a conspicuous broad, white, scarious margin surrounding the central black triangle

With an inconspicuous narrow scarious margin; often with orange tinge around base of sheath

With an inconspicuous, very narrow scarious margin; often with orange tinge around base of sheath

Lowest branch internode

Much shorter than adjacent stem sheath

About the same length as, or slightly longer than, adjacent stem sheath

About same length as adjacent stem sheath

Branch teeth

Usually blackish tipped, with a scarious margin, clasping branch axis

Pale, usually lacking black tips and with spreading tips

Usually blackish tipped, with a scarious margin, clasping branch axis

T.S. of stem internodes: (a) Equisetum arvense, (b) E. × litorale, (c) E. palustre, (d) E. × dycei. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 6. Other hybrids Hybrids of E. telmateia Ehrh. with E. sylvaticum (E. × bowmanii C. N. Page), with E. palustre (E. × fontqueri Rothm.), and with E. fluviatile (E × willmotii C. N. Page) are not described here as they are clearly intermediate between the parents and show the pale or white chlorophyll-free stems of E. telmateia. References FitzGerald, R. & Jermy, A. C. (1987). Pteridologist 1(4): 178-181. Jermy, A. C. (1996). British Wildlife, 8(1): 37-41. M erryweather, J. (1992). The fern guide. Field Studies Council, Shrewsbury. Page C. N. & Barker, M . (1985). Proceedings of the Royal Society of Edinburgh B, 86: 265-272. Authors

A. C. Jermy, C. N. Page & P. J. Acock, January 1998.

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Plant Crib

ERICA 1. General A useful account of identification of the native species in Britain and Ireland with illustrations is given in Turpin, P. G. (1990). The Wild Heathers of the British Isles. In: A guide to some difficult plants. Pp. 109-119. Wild Flower Society, London. 2. Erica ciliaris / E. tetralix / E. × watsonii Erica tetralix and Erica ciliaris are easily distinguished, but hybridise freely and in many populations there is extensive introgression (Gay 1960, Chapman 1975). The hybrid E. ciliaris × E. tetralix = E. × watsonii Benth. shows a wide range of forms with characters intermediate between its parent species. The commonest form bears the characters of E. ciliaris, but with an inflorescence approaching that of E. tetralix. The best characters are the inflorescence, and the appendages on the anthers (Figs. a-c): in E. ciliaris these appendages are absent, in E. tetralix they are well developed (more than ½ the length of the anther), and in hybrids the appendage is present but in a much reduced form. The number of leaves in a whorl is not a reliable character. E. ciliaris occurs on moist heathlands in Dorset where populations have spread since Bronze Age times. It is found in lesser amounts in Cornwall, Hampshire, Devon and W. Galway. Changes in distribution and abundance of populations in Dorset are described by Chapman & Rose (1994), and its overall ecology by Rose et al. (1996). The establishment of hybrids within populations is encouraged by heathland fires.

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Plant Crib Erica ciliaris L.

Erica tetralix L.

Leaves

Broadly ovate (only twice as long as broad); midrib on lower side of leaf glabrous; usually 3 to a whorl

Linear-lanceolate (at least three times longer than broad); midrib on lower side of leaf pubescent; usually 4 to a whorl

Branches

Short, numerous, tending to be whorled under the current inflorescence

Few, long, not tending to be whorled, usually distant from the current inflorescence

Inflorescence

A unilateral raceme

An umbel

Corolla

Tubular-urceolate, 8-10 mm, ventricose, mouth oblique

Ovoid-urceolate, 6-8 mm, not ventricose, mouth may be slightly oblique

Anthers

Without appendages (note 1) (Fig. a); surface papillate

With appendages more than halflength of the anther (Fig. c); surface not papillate

Capsule

Glabrous

Pubescent

Note 1.

Character is intermediate when appendage is present but less than half of the length of the anther; (Fig. b).

Anthers showing appendages (a) E. ciliaris, (b) E. × watsonii, (c ) E. tetralix.

References Chapman, S. B. (1975). Journal of Ecology 63: 809-824. Chapman, S. B. & Rose, R. J. (1994). Watsonia 20: 89-95. Gay, P. A. (1960). New Phytologist 59: 218-226. Rose, R. J., Bannister, P. & Chapman, S. B. (1996). Journal of Ecology 84: 617628. Author

S. B. Chapman, November 1997.

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Plant Crib 3. Erica mackaiana / E. tetralix / E. × stuartii E. mackaiana and its hybrid with E. tetralix are of local occurrence on bogs in Galway, Donegal and M ayo, and can be distinguished using the Table below. Erica mackaiana prefers better-drained sites to E. tetralix, typically on old hand-cut turf banks, edges of ditches and lake edges. E. × stuartii is more widespread and closer in habitat preference to E. tetralix (e.g. wet bogs, flat lawns but not pools). E. mackaiana Bab.

E. × stuartii (Macfarl.) Mast.

E. tetralix L.

Irregular

Intermediate

Branches few, usually distant from inflorescences

Internode All the same length

Intermediate

Internodes immediately below inflorescences longer than those lower down on the stem

Stem leaves

Spreading

Narrow and erect

Appressed

Ovary

Glabrous

A few hairs on upper part of the ovary

Pubescent

Pollen

Partially fertile

Sterile

Fully fertile

Set seed

On very rare occasions

Fails

Regular

Branchin g pattern

References Gay, P. A. (1957). Aspects of the phytogeography of some Lusitanian Ericaceae of the British Isles. Ph.D. thesis, University College, London. Glanville, E. (1957). Erica mackaiana and other Irish heaths. B. A. (M od) thesis, Trinity College, Dublin. Van Doorslaer, L. (1990). The ecology of Erica mackaiana Bab. with reference to its conservation in Connemara (Ireland). Ph.D. thesis, University College, Galway. Webb, D. A. (1955). Journal of Ecology 43: 319-330. Authors

L. Van Doorslaer & M . Sheehy Skeffington, January 1998.

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Plant Crib

ERIOPHORUM The main problems usually encountered are in distinguishing E. latifolium or E. gracile from E. angustifolium. The following Table and illustrations should help. E. vaginatum

E. angustifolium

E. latifolium

E. gracile

Growth form

Dense tussocks

Rhizomatous

Laxly caespitose Rhizomatous

No. of heads

1

1 to 7

2 to 12

3 to 6

Leaf shape 1-2 mm wide, trigonous

3-5 mm wide, canaliculate

3-8 mm wide, flat

1-2 mm wide, 3angled

Peduncle

Smooth

Smooth

Scabrid

Scabrid

Pappus hairs

Simple

Simple

Forked at ends

Simple

Typical habitats which may help pick out E. latifolium and E. gracile are as follows: Eriophorum vaginatum L.: On acidic peat in bogs and mires, rarely wet heathland. Eriophorum angustifolium Honck.: Widespread in bogs, fens, dune slacks, etc., usually on peaty soils on pools. Eriophorum latifolium Hoppe: Fens, calcareous flushes, bare stony non-calcareous flushes, dune slacks, often on firm ground. Eriophorum gracile W. D. J. Koch ex Roth: Very wet poor fen communities in swampy conditions of medium pH. References Byfield, A. (1991). British Wildlife 3: 37-40. Conaghan, J. P. (1995). The ecology of Eriophorum gracile and E. latifolium in Ireland. PhD thesis, University College, Galway. Authors

J. P. Conaghan, C. Dalby, M. Sheehy Skeffington & T. C. G. Rich, January 1998.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib E. angustifolium

E. latifolium

E. gracile

Eriophorum angustifolium (a) stem (× × 5), (b) cotton tip (× × 50), (c ) glume (× × 3), (d) peduncle (× × 10), (e) upper leaf tip (× × 2), (f) upper leaf sheath and sheath (× × 2), ligule, (g) habit (× × 0.1). E. latifolium (h) cotton tip (× × 50), (i) glume (× × 3), (j) peduncle (× × 15), (k) upper leaf tip (× × 2), (l) upper leaf (× × 2), (m) stem (× × 5), (n) habit (× × 0.1). E. vaginatum (o) glume (× × 3), (p) leaf section (× × 5), (q) habit (× × 0.1). E. gracile, (r ) glume (× × 3), (s) peduncle (× × 15), (t) stem (× × 5), (u) habit (× × 0.1). Illustrations © C. Dalby, reproduced with permission from British Wildlife.

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ERODIUM

The four native taxa can be separated using the key below (Stace’s New Flora also includes eleven introduced species). Note that E. cicutarium is now split into E. cicutarium s.s. and E. lebelii (E. glutinosum Dumort.), and E. cicutarium subsp. dunense has too many intermediates to merit recognition (Stace’s New Flora). In E. lebelii and E. cicutarium, glandulosity, size of flowers and number of flowers in an inflorescence are unsatisfactory characters. Starved E. lebelii is often sparsely glandular, as are barren first year plants of both species. Starved E. cicutarium often has solitary flowers. Well-grown E. lebelii may have flowers 12 mm across, and 5 in an inflorescence. The hybrid between E. lebelii and E. cicutarium is intermediate but has showy inflorescences of large flowers with persistent petals, and is highly if not completely sterile. Pollen grains vary in size (20-75 µm) and colour (yellow to red) in the same anther. Fruits are mostly not developed. It occurs occasionally with the parents. Typical E. maritimum is distinct at a glance, but E. moschatum looks like a robust E. cicutarium / E. lebelii. When collecting material for identification, include mature fruits and note petal colour. 1 1

2

2

3

3

Leav es simple or lobed to c. ½ way (Fig. c); petals shorter than sepals, usually incomplete or absent; mericarps (carpels) c. 2.5 mm, beak c. 8 mm. Mostly S & W coasts of Britain (Scarce Plants), and IrelandE. maritimum (L.) L'Hér. Leav es pinnate with pinnatif id leaf lets (Figs. d-f ); petals longer than sepals, alway s 5; mericarps 4-6 mm, beak 16-30 mm or more 2 Apical pits of mericarps conspicuous with a raised sharp edge surrounded by an equally sharp-edged f urrow so that each pit looks like two pits, one superimposed on the other (Fig. a); pit and f urrow with shining sessile glands; most of the leaflets div ided to less than ½ way (Fig. d). Mostly S & W coasts of Britain (Scarce Plants), and IrelandE. moschatum (L.) L'Hér. Apical pits of mericarps with or without a glabrous, weakly f urrowed surrounding zone; apical pits without glands; leaflets pinnatif id to 2-pinnatif id, most leaflets cut to more than ½ way (Figs. e, f) 3 Mericarps 5-6 mm, beak (20-)23-30 mm; apical pits 2/3 maximum diameter of mericarp, sharp-edged and surrounded by a glabrous weakly f urrowed zone, the hairs of the mericarp not projecting ov er the edge of the pit; petals mauv e, the two upper of ten slightly smaller, darker-coloured and with a colourless (rarely black-centred) spot at the base; stigmas purple; nectaries dark purple, slightly broader than long with a rounded or truncate apex (if petals whitish then plant semi-albino with pale green stems, greenish white stigmas and y ellow nectaries); enlarged base of f ertile f ilaments with straight sides and sloping to squared ‘shoulders’; pollen 56-62 µm; dry seeds 2.5-3.0 mm. Dry pastures, waste ground, dunes, sea cliffs, widespread E. cicutarium (L.) L'Hér. s.s. Mericarps 4-5 mm, grey -brown, beak 16-21 mm; apical pits minute, to 1/3 maximum diameter of mericarp, weakly defined, not surrounded by a glabrous f urrowed zone (Fig. b), the hairs of the mericarp slightly projecting ov er the edge of the pit; petals pale lilac, unspotted; stigmas pink; nectaries much broader than long, with retuse apex, dark purple; enlarged base of f ertile f ilaments with rounded sides and usually a tooth on one or both sides; pollen 47-52 µm; dry seeds 2.2-2.5 mm. Larger coastal dune systems in S & W Britain and Ireland, usually with E. cicutarium s.s.

E. lebelii Jord.

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Plant Crib

Mericarps (a) E. moschatum, (b) E. cicutarium s.s., (c) E. lebelii (del. P. M. Benoit)

Reference

Benoit, P. M. (1967). Proc. BSBI 6: 364-366.

Author

P. M. Benoit, March 1998.

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Plant Crib

EUPHORBIA 1. Euphorbia oblongata / E. dulcis / E. hyberna E. oblongata may be more widely locally naturalised than has been realised, and may be confused with E. dulcis or possibly E. hyberna. The following key should help to separate them (Barrett 1996; see also Stace’s New Flora 2nd edition, 1997). 1

Capsule sparsely tuberculate with ± hemispherical tubercules; f lowering bracts y ellowish green

1

Some of the tubercules on capsule at least twice as long as wide, often f iliform

2

Stems persistently scaly at base; flowering bracts green to purplish

2

Stems not persistently scaly at base; flowering bracts bright y ellow

E. oblongata Griseb.

Reference

Barrett, D. (1996). BSBI News 71: 46-48.

Author

D. Barrett, January 1997.

2

E. dulcis L. E. hyberna L.

2. Euphorbia paralias / E. portlandica These species can sometime be difficult to tell apart though the larger erect habit of E. paralias is usually distinctive (E. portlandica can be quite variable in habit). The prominence or otherwise of the midrib is often difficult to assess. Leaf shape is variable but can still be used to separate the species, but it is less clear on the lower stem leaves; the upper leaves of E. paralias are different to the lower ones which are smaller and may be obovate. M aps of both species are given in Scarce Plants. E. paralias L.: Leaves thick and succulent; upper leaves oblong, ovate or lanceolate, midrib obscure on lower side of leaf, with an acute to retuse apex (Fig. a); seeds smooth. M ostly on sand dunes. E. portlandica L.: Leaves thinner and not succulent, upper and lower leaves obovate to oblanceolate, midrib more prominent on lower side of leaf often ending in a small apiculate point on some leaves, especially the lower (sometimes with several teeth) (Fig. b); stems often reddish; seeds pitted. Common on cliffs and dunes.

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Plant Crib

a

b

Euphorbia leaves (a) E. paralias (upper leaves), (b) E. portlandica.

3. Euphorbia esula / E. × pseudovirgata / E. cyparissias There has been much dispute over the limits of the taxa in this group, but recent research into the E. esula aggregate has clarified the situation (Watson 1985; Crompton, Stahevitch & Wojtas 1990). The commonest member of the aggregate in Britain and Ireland by far is E. × pseudovirgata (E. esula × E. waldsteinii). The original hybrid swarm appears to have arisen in the Danube basin where Austria, Czech Republic and Hungary meet. It has since spread through these countries as well as Poland, Rumania and Bulgaria. E. waldsteinii (E. virgata Waldst. & Kit.) has now been confirmed from V.c. 69 and 77 and E. × gayeri (E. cyparissias × E. waldsteinii) has been confirmed from V.c. 42 and V.c. 70. E. × pseudoesula (E. cyparissias × E. esula) has been reported in Suffolk, Surrey and S Wales. These are included in Stace’s New Flora 2nd edition (1997). E. esula var. pseudocyparissias was a name formerly applied to a variety of taxa including E. esula, E. cyparissias, E. × pseudovirgata and possibly E. × pseudoesula; such records need to be reassessed. The taxa may be identified as follows: E. cyparissias L.: Stem leaves linear, up to 2 mm wide (Fig. a). E. esula L.: Leaves linear-oblanceolate or linear-oblong, commonly 5-10 mm wide, broadest above the middle, tapering to the base, sessile (Fig. b). E. × gayeri Boros & Soó: Leaves intermediate between E. cyparissias and E. waldsteinii, c. 2-3 mm wide, widest below the middle (not illustrated). E. × pseudoesula Schur: Leaves intermediate between E. cyparissias and E. esula, oblanceolate to oblong-lanceolate, widest above the middle (not illustrated). E. × pseudovirgata (Schur) Soó - leaves linear to narrowly linear, parallel-sided, c. (3-)4-5 mm wide, rounded at base (Fig. c). E. waldsteinii (Soják) Czerep.: Leaves lanceolate to ovate-lanceolate, 5-15 mm wide, broadest below the middle, some leaves widening slightly at the rounded to shallowly cordulate base, petiole very short (Fig. d). Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

Euphorbia leaves (a) E. cyparissias, (b) E. esula, (c) E. × pseudovirgata, (d) E. waldsteinii.

The following taxa are not currently known in Britain: E. uralensis Fisch. ex Link is not (as Flora Europaea has it) conspecific with E. waldsteinii, but is a distinct species indigenous to Russia, central Asia and Siberia. It is not found in western Europe. E. tommasiniana Bertol. should not be considered a subspecies of E. esula as given in Flora Europaea, but it is better regarded as a microspecies or a variety of E. waldsteinii indigenous to the ItalianYugoslav border. If reduced to varietal status it would have to be called E. waldsteinii var. montana. It does not occur in Britain or Ireland. References Crompton, C. W., Stahevitch, A. E. & Wojtas, W. A. (1990). Canadian Journal of Botany 68: 1978-1988. Radcliffe-Smith, A. (1981). Kew Bulletin 36: 216. Watson, A. K. ed. (1985). Leafy Spurge. Weed Science Society of America M onograph series, No. 3. Champaign, Illinois. Author

A. Radcliffe-Smith, January 1988, updated T. C. G. Rich, 1998.

4. Euphorbia amygdaloides Euphorbia amygdaloides L. subsp. robbiae (Turrill) Stace is treated as a separate species by some authors. In addition to the account in Stace’s New Flora there is a very helpful account of how to distinguish it from subsp. amygdaloides in BSBI News 76: 58-60 (1997).

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FALLOPIA

1. Fallopia × bohemica Fallopia × bohemica (F. japonica × F. sachalinensis) is widely established in Britain but is probably under-recorded (Bailey et al. 1996). Voucher material from Ireland is required. The most reliable characters for the identification of Fallopia hybrids are leaf shape, size, and the type of hair on the lower leaf surface. It is most important that only fully mature basal leaves are examined since early season leaves and leaves from the upper part of the plant are extremely variable and of little use for identification. When gathering material for herbarium specimens always include some of the biggest lower leaves available. It should be noted that absence of good seed-set is not a sign of hybridity in this genus, for, although F. japonica × F. sachalinensis is much less fertile than its parents, even the parents set no or very little seed in most localities in the British Isles. F. sachalinensis (F. Schmidt ex Maxim.) Ronse Decr.

F. × b ohemica (Chrtek & Chrtková) J. P. Bailey

F. japonica (Houtt.) Ronse Decr.

Habit

Striking, gigantic plant to 4 m in suitable sites

Intermediate, 2.5-4 m

Smaller, 2-3 m

Lower leaves

Ovate to oblong, base cordate, apex acute; up to 40 × 22 cm, length:width ratio c. 1.5-1.7, undersides of leaves with scattered, long, flexuose hairs

Intermediate in size and shape, weakly to moderately cordate at base, apex acuminate; up to 23 × 19 cm, length:width ratio 1.11.6; undersides of larger leaves with numerous short stout hairs (× 10 lens)

Ovate, base truncate, apex acuminate; 10-15 cm long, length:width ratio 1-1.5; undersides entirely glabrous

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Plant Crib Flowers

M ale fertile flowers (with exserted anthers) and male sterile flowers (with small, empty included anthers and well developed stigmas) borne on separate plants

M ale fertile and male sterile flowers borne on separate plants

Flowers usually male sterile

F. japonica × F. baldschuanica (Regel) Holub is at present only known from a single plant in London (Bailey 1993), but since seed of this hybrid has been collected from F. japonica plants all over the country it could theoretically turn up anywhere. Superficially it resembles F. japonica in habit, but with more slender stems up to 2 m long, arching over almost to touch the ground; leaves ovate to narrowly ovate-oblong, with an acuminate tip and a truncate base, almost triangular, size up to 13 × 6.5 cm. There is little chance of mistaking this herbaceous plant for F. baldschuanica, a scrambling woody perennial. There is, however, more than a chance of mistaking regrowth from weed-killed F. japonica for this hybrid, so do not be fooled by weedy shoots pushing their way through the tarmac next to stands of F. japonica! F. sachalinensis × F. baldschuanica may be awaiting discovery; it is similar to the above, but with larger leaves. References Bailey, J. P. (1993). Urban Nature 1: 50-51. Bailey, J. P., Child, L. E. & Conolly, A. P. (1996). Watsonia 21: 187-198. Author

J. P. Bailey, 1997.

2. Fallopia convolvulus / F. dumetorum The two species were frequently confused in the past, partly on account of the emphasis once placed on the winged perianth of F. dumetorum, a feature that can be present also in F. convolvulus. The following key indicates how distinct these two species are:1

Fruiting pedicels 1-3 mm; nut 4-5 mm, f inely punctate, dull

1

Fruiting pedicels (3-)5-8 mm; nut 2.5-3 mm, smooth, glossy

F. convolvulus (L.) Á. Löve F. dumetorum (L.) Holub

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Plant Crib

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Plant Crib The outer perianth-segments of F. dumetorum are always broadly winged in fruit, the wings decurrent on the pedicel. The outer perianth-segments of F. convolvulus are usually keeled or narrowly winged, but in var. subalatum (Lej. & Courtois) D. H. Kent, a generally robust variant of rich soils, they are welldeveloped and give the plant something of the appearance of F. dumetorum. F. convolvulus is a weed of disturbed ground, whereas F. dumetorum is a plant of hedges and woodland margins. F. dumetorum is a very locally distributed, declining plant (Scarce Plants). The population sizes can vary enormously from year to year related to coppicing cycles or hedge clearance and it may be necessary to revisit some sites regularly. In some areas, such as Sussex, the best way to spot the plant is to look for the sinuous shoots spreading out from hedge tops. Full details of all sites should be recorded. Author

J. R. Akeroyd, October 1997.

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Plant Crib

FUMARIA The following key to Fumaria covers the species and infraspecific taxa of Fumaria recognised following a revision of Pugsley's (1912) monograph. An account of the F. bastardii/F. muralis complex is given by Sell (1989). It is often easier to name infraspecific taxa than the actual species, hence these are all included. When collection herbarium material, please include mature fruits and describe the flower colour carefully (annotated drawings may help). Flower characters are the most important and the other characters are subsidiary. When measuring flowers, a number of different flowers from different inflorescences should be selected. 1

1

Leaf lobes f lat, oblong, lanceolate or cuneif orm (see Figs. g-k); at least some corollas more than 9 mm long; wings of the upper petal turned upwards; lower petal not spathulate (except F. painteri and F. muralis subsp. muralis v ar. cornubiensis); fruits smooth or rugose when dry 2 Leaf lobes channelled or f lat, narrower, lanceolate, linear-oblong or linear; corolla not more than 9 mm; wings of the upper petal with broad margins or more or less patent; lower petal distinctly spathulate; f ruits more or less rugose when dry 20

2

Wings of upper petal dark purple with a broad white margin; lower petal with broad patent margin; f ruit c. 3 x 3 mm

2

Wings of upper petal nev er dark purple with a broad white margin; lower petal with a narrow margin; f ruit c. 2.0-2.5(-2.7) x 2.0-2.5(-2.7) mm 3

F. occidentalis

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Plant Crib

3 3

4 4

Pedicels rigidly recurv ed in f ruit; peduncles equalling or longer than raceme; f lowers numerous, about 20 or more; fruit with a distinct f leshy neck when fresh (Fig. d) 4 Pedicels rarely recurv ed in f ruit and then usually f lexuous; either peduncles shorter than raceme or f lowers few, about 12; fruit with an indistinct f leshy neck (Figs. e, f) 8 Corolla pale to deep purple; inf lorescence rather lax; upper petal broader and not laterally compressed with wings exceeding the keel F. purpurea Corolla usually creamy , sometimes with a reddish suf f usion, rarely red or tinted pink; inf lorescence rather dense; upper petal dorsally very narrow and laterally compressed with wings not exceeding the keel 5

F. capreolata 5 5

Flowers deep crimson F. capreolata Flowers creamy white or slightly tinted red or pink

subsp. capreolata forma speciosa 6

6

Sepals 4.0-6.5 x 2-4 mm; f ruit c. 2 x 2 mm or smaller, subglobose, apex v ery obtuse but not truncate, smooth when dry

6

Sepals f requently narrower; f ruit c. 2.5 x 2.5 mm, of ten truncate at apex and more or less rectangular in outline, frequently f aintly rugulose when dry 7

7

Corolla creamy white, sometimes slightly tinted red; pedicels usually rigidly arcuate-recurv ed; f ruits more or less rectangular in outline and truncate at apex F. capreolata subsp. babingtonii var. babingtoni i Corolla tinted with pink; pedicels less recurv ed; f ruits rounded but scarcely truncate at apex and rounded in outline

F. capreolata subsp. capreolata forma capreolata

7

F. capreolata subsp. babingtonii var. devoniensis 8 8

9 10

Lower petal more or less spathulate (Figs a, b) Lower petal not spathulate (Fig. c)

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Plant Crib 9 9

Corolla 8.5-10 mm; sepals 3.5-4.0 x 2.0-2.5 mm F. Corolla 10-11 mm; sepals 3.0-3.5 x c. 1.5 mm

muralis subsp. muralis var. cornubiensis F. × painteri

10 Sepals 2.0-3.5 mm, elliptical, more or less serrate; bracts less than 1/2 as long as pedicel; upper petal laterally compressed; lower petal with patent margins; f ruits rugose when dry 11 10 Sepals 2.7-5.0 mm, elliptical or ov ate, sub-entire or dentate; bracts more than 1/2 as long as pedicel; upper petal more or less dorsally compressed; lower petal with erect or patent margins; f ruits smooth or slightly rugulose when dry 13

F. bastardii F. bastardii var. bastardii 12

11 Upper petal without blackish wings 11 Upper petal with blackish wings

12 Plants rather dwarf; corolla rather blunt at apex; f ruits c. 2 x 2 mm F. bastardii 12 Plant dif f use and straggling; corolla v ery acute at apex; f ruits c. 2.5 x 2.5 mm

var. gussonei

F. bastardii var. hibernica F. muralis/F. reuteri (some forms of F. muralis also key out elsewhere) l4 l5

13 Sepals entire or nearly so; racemes much exceeding peduncles in length 13 Sepals dentate; raceme shorter than or equalling peduncles in length 14 Sepals 3-5 mm; corolla 11-13 mm; lower petals with patent margins 14 Sepals 2.7-3.0 mm; corolla c. 10 mm; lower petal with erect margins

F. reuteri F. muralis subsp. neglecta 16 18

15 Sepals 4.0-5.0 x 2.5-3.0 mm 15 Sepals 3.0-4.0 x 1.5-2.7 mm 16 Fruits c. 2.5 x 2.5 mm, nearly square in prof ile, slightly rugulose when dry

F. muralis subsp. boraei var. ambigua 17

16 Fruits c. 2.5 x 2.0 mm, obovate and rounded-obtuse in profile, usually smooth when dry

17 Plant robust; pedicels stout; corolla 10-12 mm, rose-pink F. muralis subsp. boraei var. major 17 Plant slender; pedicels slender; corolla 10-11 mm, pale pink F. muralis subsp. boraei var. gracilis 18 Fruits 1.7-2.0 x 1.7-2.0 mm, subglobose to subglobose-obov oid

F. muralis subsp. boraei var. britannica 19

18 Fruits 2.0-2.5 x 1.7-2.0 mm, ov oid-orbicular, subacute or apiculate

19 Corolla 9.0-11.0 mm, pale pink; wings of upper petal not particularly broad; lower petal with narrow erect margins

F. muralis subsp. muralis var. muralis 19 Corolla 8.5-10 mm, Iliac-pink; upper petal with broad wings; lower petal sub-spathulate with patent margins

F.

muralis subsp. muralis var. cornubiensis 21 24

20 Sepals not more than 1.2 x 1.0 mm; corolla 5-6 mm 20 Sepals at least 1.5 x 1.0 mm; corolla at least 6 mm

21 Leaf -lobes f lat; racemes shortly peduncled; bracts shorter than pedicels in f ruit; f lowers pale pink

F. vaillantii 21 Leaf lobes channelled: racemes subsessile; bracts equalling or longer than pedicels in f ruit; f lowers white or tinged with pink

22 F. parviflora F. parviflora var. acuminata 23

22 Fruit acute at apex 22 Fruit rounded or with a beak at apex

F. parviflora var. parviflora F. parviflora var. symei

23 Fruit rounded at apex 23 Fruit with short beak at apex

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Plant Crib 24 Sepals 3.5-4.0 x 2.0-2.5 mm; f ruits smooth when dry F. muralis subsp. 24 Sepals 1.5-3.5(-4.0) x 0.7-3.8 mm; fruits rugose when dry

muralis var. cornubiensis 25

25 Leaf -lobes channelled; bracts longer than pedicels; fruit rounded at apex 25 Leaf -lobes flat; bracts shorter than pedicels; f ruit truncate or retuse at apex

F. densiflora 26

F. officinalis 27 28

26 Racemes 20- to 60-f lowered; sepals 2.5-3.8 x 0.9-2.2 mm 26 Racemes 5- to 20-f lowered; sepals 1.2-2.5 x 0.7-1.9 mm 27 Pedicels robust; corolla 7-9 mm, purplish-pink; f ruits c. 2.0 x 2.5-3.0 mm

F. officinalis var. officinalis 27 Pedicels slender; corolla c. 7 mm, pale purplish-pink; f ruits c. 2.0 x 2.5 mm

F. officinalis var. elegans 28 Leav es glaucous; corolla pale pink; f ruits c. 2.0 x 2.5-3.0 mm, obrenif orm in outline, retuse at apex

F. officinalis var. minor 28 Leav es less glaucous; corolla deeper pink; f ruits 2.0-2.5 x 2.0-2.5 mm, rounded, truncate but not retuse at apex and often with a small persistent apiculus F. officinalis var. wirtgenii

References Pugsley, W. H. (1912). Journal of Botany 50: 1-76. Sell, P. D. (1989). BSBI News 51: 24-26. Author

P. D. Sell, January 1988.

Distribution of Fumaria taxa

The taxa are listed below in alphabetical order with notes on their distribution. M any of the endemic varieties have not been recorded recently. F. bastardii Boreau: widespread (Scarce Plants). var. bastardii: widespread in Britain, Ireland and Europe. var. gussonei (Boiss.) Pugsley: Channel Islands and Scilly, and M editerranean. var. hibernica (Pugsley ex Praeger) Pugsley: western Britain and Ireland, endemic.

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Plant Crib

Silhouettes of Fumaria sepals (M. G. Daker, December 1997).

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Plant Crib F. capreolata L. (Scarce Plants). subsp. babingtonii (Pugsley) P. D. Sell: Scattered through Britain and Ireland, often near coast. var. babingtonii: Scattered through Britain and Ireland, mostly near coast. var. devoniensis Pugsley: Devon. subsp. capreolata: Channel Islands and Europe. forma capreolata: Channel Islands and Europe. forma speciosa Pugsley: Channel Islands and Europe. F. densiflora DC.: mostly S England and E Scotland, scattered elsewhere (Scarce Plants). F. muralis Sond. ex W. D. J. Koch subsp. boraei (Jord.) Pugsley: widespread in Britain and Ireland. var. ambigua Pugsley: S Britain? var. britannica Pugsley: S Britain. var. gracilis Pugsley: S Britain. var. major (Boreau) P. D. Sell: S Britain? subsp. muralis: scattered in S Britain, possibly now extinct (Critical Supplement). var. muralis: scattered in S Britain (Critical Supplement). var. cornubiensis Pugsley: Cornwall, endemic, probably extinct. subsp. neglecta Pugsley: Cornwall (Critical Supplement), endemic, possibly extinct. F. occidentalis Pugsley: Cornwall and Scillies, endemic Red Data Book Species: please document all localities. F. officinalis L.: Widespread. var. elegans Pugsley: mostly SE England. var. minor Hausskn.: mostly SE England, but throughout Britain and Ireland. var. officinalis: widespread. var. wirtgenii Hausskn.: mostly SE England but perhaps over-looked elsewhere. Ireland. (Critical Supplement). F. × painteri Pugsley: scattered in S Britain (Critical Supplement), possibly extinct. F. parviflora Lam.: mostly S England, rare on E coast (Scarce Plants). var. acuminata Clavaud: mostly S England. var. parviflora: mostly S England. var. symei Pugsley: Cambridge, endemic. F. purpurea Pugsley: Endemic, scattered in Britain, Ireland and Channel Islands: possibly over recorded in Lancashire recently and requiring verification. F. reuteri Boiss. (F. martinii Clavaud) is protected under Schedule 8 of the Wildlife & Countryside Act 1981 and must not be collected. Once scattered in S England, now Cornwall and I of Wight only: could be over-looked elsewhere. F. vaillantii Loisel.: S England and Europe (Scarce Plants).

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Plant Crib

GAGEA LUTEA / HYACINTHOIDES NON-SCRIPTA, VEGETATIVE Early in the season or as it may be shy flowering, Gagea lutea leaves may be confused with young Hyacinthoides leaves or seedlings. The species are easily separable on leaf venation, which is sometimes more easily felt than seen. Even leaves of young Gagea bulbs 1 mm wide are strongly ribbed, whereas those of Hyacinthoides tend to be semi-cylindrical. The latter also have a stringy, sticky sap which exudes once the leaves are broken; this is absent in Gagea. Gagea lutea (L.) Ker Gawl.: 3-5(-7) veined underneath (Fig. a); leaf apex shortly hooded (Fig. b). Hyacinthoides non-scripta (L.) Chouard ex Rothm.: 1 veined underneath (Fig. b); leaf apex acute not hooded (Fig. b). Later in the season, Gagea can be picked out from several yards away as the leaves tend to be upright turning over towards the tip, are glossy, broadest near the apex, and sometimes go brown at the tips. By contrast, Hyacinthoides leaves tend to flatten against the ground, are dull and parallel sided.

a

b

c

d

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GERANIUM Yeo, P. F. (1985) Hardy Geraniums (Croom Helm, London, re-published with minor corrections 1992 by Batsford, London) is an excellent monograph which is invaluable for naming garden escapes as well as native taxa. When collecting material please press a few petals separately, with colour notes, and count the stamens. Ripe fruit should be collected too if possible. 1. Vegetative rosettes Vegetatively, many Geranium species can be identified from leaf shape alone though the shapes of most species vary with age and habitat, and many species such as G. sanguineum vary markedly between populations. The following basal leaf shapes may help to distinguish some taxa - in flower or fruit they can be keyed out satisfactorily in Stace’s New Flora or Yeo (1985) as above. Upper leaves tend to be more finely divided in all species and often differ in shape from the lower leaves. In disturbed habitats and near habitation there may be garden escapes and aliens, which are not illustrated here, though their leaf shapes look different to native taxa illustrated below. The shiny leaves of G. lucidum are also distinctive enough not to need inclusion. Note that the scales used in the drawings differ; very crudely G. sylvaticum and G. pratense have large leaves c. 8-15 cm across, G. sanguineum and G. pyrenaicum medium sized leaves c. 3-10 cm across and the annual species small leaves c. 2-5 cm across.

1a. Geranium sylvaticum / G. pratense The degrees of dissection are a little more variable than often quoted in Floras for both species, but the leaf shapes should allow them to be separated at a glance as below. Although G. sylvaticum is predominantly a plant of upland ledges, woods and hay meadows and G. pratense a plant of lowland meadows and verges, they may grow together.

Geranium sylvaticum L. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Geranium pratense L.

1b. Geranium sanguineum This species has a distinctive leaf shape and is unlikely to be confused with other taxa. When recording please distinguish native colonies from garden escapes.

1c. Geranium pyrenaicum The leaves of Geranium pyrenaicum Burm. f. are rather like a large G. dissectum in lobing but are generally twice the size. It has a mixture of short glandular, short and long eglandular hairs on the petioles and long, eglandular, curved to appressed hairs and small, glandular hairs on the leaf surfaces.

G. pyrenaicum

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Plant Crib 1d. Geranium rotundifolium / G. columbinum / G. dissectum / G. pusillum / G. molle The following notes are provisional and need detailed studies early in the season in the field. These taxa occur in short, open grassland and are similar vegetatively when basal rosettes only are present, and some of them are easily confused in flower too. The small glandular hairs are best seen with a microscope, though they can sometimes be felt. All species may be glandular on the stems and flowering/fruiting parts above, but they seem variably glandular below. G. columbinum and G. pusillum are the most distinct vegetatively and it should be possible to identify them reliably from careful examination of leaves alone. G. columbinum has the most dissected leaves and is especially distinctive in the field; the finely divided leaves with only appressed, short, stiff, eglandular hairs should distinguish it (hairs deflexed to spreading in other taxa). G. pusillum has moderately divided leaves similar to the other species but has distinctive hair type composed of uniform short, ± deflexed to patent, eglandular hairs (glandular hairs may also be present) (mixture of hair types in other remaining taxa). Having eliminated these two species, three remain. G. rotundifolium has rosette leaves very similar to those of G. pusillum and G. molle, though they tend to be larger than in G. molle and have a quadrate (almost square) middle lobule of the major lobes, whereas in G. molle this lobule is ± similar to those flanking it (P. Oswald, pers. comm. 1998). The truncate to cuneate stem leaves which develop later are instantly recognisable (see Figure below), and it tends to lack the long, eglandular hairs of G. molle and G. dissectum, and looks less shaggy once the species are known. Except in deep shade, it normally has a small red spot at the base of each sinus of the rosette leaves, though this may also rarely be present in G. molle (Oswald 1996).

G. columbinum L. (eglandular, short, stiff, appressed hairs only; not glandular)

G. dissectum L. (variable, but usually a mixture of long and short eglandular hairs; short glandular hairs present or not). By the time it begins to flower the leaves can look similar to the winter leaves of G. columbinum, but can be separated on the hairs.

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Plant Crib

G. pusillum L. (uniform deflexed to patent, short, eglandular hairs; short glandular hairs present or not; rarely glabrous)

G. molle L. (mixture of long silky and shorter eglandular hairs; short glandular hairs usually present)

G. rotundifolium L. (medium and short length eglandular hairs; glandular hairs present or not), basal leaves

G. rotundifolium, stem leaves

The two commonest species G. molle and G. dissectum are both variable and can be very difficult to separate vegetatively. G. molle tends to be glandular with leaves cut to c. ½ way, and is often soft and greyish in the field from the dense hairs. G. dissectum is very variable in hair type, and the leaves are usually cut to c. 3/4. Reference Authors

Oswald, P. (1996). Nature in Cambridgeshire 38: 62-64. T. C. G. Rich & J. L. Carey, 1997.

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Plant Crib 2. Geranium purpureum / G. robertianum Geranium purpureum is easily overlooked as G. robertianum (and visa versa in coastal forms), and the infraspecific taxa of the latter are often not recorded. In particular, populations near the sea (especially in southern England and Ireland) should be investigated. The following key includes infraspecific taxa recognised by Baker (1955, 1956) updated with Yeo (1973). Note that fruits of both species may be glabrous or hairy. 1 1

Undehisced anthers y ellow; pollen y ellow; petals 5-9.5 mm long; f ruits with 3-5 pronounced ov erlapping collars/ridges at apex (Figs. a-d) (see also notes 1-3) (G. purpureum Villars) 2 Undehisced anthers pink, orange, purple or red; pollen orange; petals (8-)9-14 mm long; f ruits with 1-2(-3) ov erlapping collars/weak ridges at apex (Fig. e) (G. robertianum L.) 3

2 2

Erect to ascending (see notes on subsp. forsteri below ) G. purpureum subsp. purpureum Prostrate, tips of shoots ascending G. purpureum subsp. forsteri (Wilmott) H. G. Baker

3

Flower diameter 1.3-1.4 cm; f ruits usually glabrous; prostrate or arcuate-ascending

3

Flower diameter 1.2-1.7 cm; fruits usually hairy; usually erect, rarely prostrate

4

Reddish only at the nodes and petiole bases, petioles coppery ; petals with wide white streaks on dorsal surf ace, flowers appearing pale pink; anthers dark red to purple

4

Stems and petioles deep dull red; f lowers pink; anthers orange to purple

G. robertianum subsp. maritimum (Bab.) H. G. Baker 4

G. robertianum subsp. celticum Ostenf. G. robertianum subsp. robertianum Notes 1. Avoid plants without any red / purple anthocyanin colouring (i.e. albinos). G. robertianum may produce small flowers with dull yellow anthers at the end of the season. 2. In addition, the flowers of the two species are different (Figs f, g), and the smaller, less spreading petals of G. purpureum are distinctive. 3. G. purpureum also has 1-5 developed internodes on the central axis and G. robertianum has 0-2 (Yeo 1973). G. purpureum subsp. purpureum is local round the coast from S Ireland to Sussex, and rarely also inland on limestone rocks. It is protected under Section 21 of the Wildlife Act 1976 in the Republic of Ireland.

Dorsal view of fruit of (a) G. purpureum subsp. purpureum, (b-d) G. purpureum subsp. fosteri to show variation transitional from the typical G. purpureum pattern (b) to a G. robertianum pattern (d), and (e) G. robertianum subsp. robertianum. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

Side view of flowers of (f) G. purpureum, (g) G. robertianum (redrawn from Yeo 1973).

G. purpureum subsp. forsteri is transitional to G. robertianum and Baker (1956) suggested it may have arisen through introgressive hybridisation of G. purpureum subsp. purpureum with prostrate forms of G. robertianum. However, plants in the Solent seen by Yeo were instantly recognisable as G. purpureum and hybridisation may not be involved. Plants may also be dwarf and bushy as an alternative to decumbent and ascending. Experiments with prostrate and erect plants from Hayling Island (V.c. 11) by D. Easton in 1989 found that both grew upright in cultivation, and seeds examined by R. P. Bowman showed no difference between the forms either (E. A. Pratt, pers. comm. 1989). However, the Hayling Island plants differ from those in Devon (Brewis et al. 1996), and further cultivation experiments and research on all the scattered populations are required. Subsp. forsteri is endemic to V.c. 11, 13 and Guernsey and extinct in the Isle of Wight. It may not merit subspecific rank. G. robertianum subsp. robertianum is widespread and common. G. robertianum subsp. maritimum occurs around the coast of Britain and Ireland on stable shingle, particularly at the rear of fringing beaches and less frequently on cliffs and seaside walls. Yeo (1973) queries whether prostrate sea-shore forms can be included in one subspecies, as coastal plants differed markedly in cultivation. G. robertianum subsp. celticum is a rare endemic of limestone in S Wales and W Ireland. Some botanists regard this as a local form. References Baker, H. G. (1955). Watsonia 3: 160-167. Baker, H. G. (1956). Watsonia 3: 270-279. Brewis, A., Bowman, R. P. & Rose, F. (1996). Flora of Hampshire. Harley Books, Colchester. Yeo, P. F. (1973). Botanical Journal Linnean Society 67: 286-346.

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GYMNADENIA CONOPSEA Three infraspecific taxa may be recognised within G. conopsea (L.) R. Br. (these may merit specific rank). The best characters are the shape and proportions of the labellum, the side lobes of the labellum (not easy to quantify) and the lateral sepals. Subsp. conopsea is found in dry lowland calcareous grassland on chalk, Oolite and M agnesian limestone northwards to Durham. Subsp. densiflora (Wahlenb.) E. G. Camus, Bergon & A. Camus occurs in calcareous fens (and also north facing chalk grassland) W to Somerset and Devon and N to Anglesey and Westmorland. Subsp. borealis (Druce) F. Rose is the predominant taxon in the N and W where it grows in relatively lime-poor hill pastures, but it also occurs in the New and Ashdown Forests on marl bogs. Hybrid swarms (showing hybrid vigour) have been found between neighbouring populations of subsp. conopsea and of subsp. densiflora. Subsp. conopsea

Subsp. densiflora

Subsp. b orealis

Labellum width

(4.5-)5.5-6.5(-7) mm, without shoulders

(5.5-)6.5-7(-8) mm, with distinct shoulders

(3-)3.5-4(-5) mm, narrow

Labellum length

(4-)5-6(-6.5) mm

(3-)3.5-4(-4.5) mm

(3.5-)4-4.5(-5) mm

Max. width across floret

(7-)10-11(-13) mm

(10-)11-13(-14.5) mm

(7-)8-10(-12) mm

Spur length

(11-)12-14(-17) mm

(13-)14-16(-17) mm

(8-)11-14(-15) mm

Lateral sepals

Linear, pointed at tip, deflexed at c. 30°, c. 1 mm wide × 5-6 mm long

Linear, truncate at tip, held horizontally, c. 1 mm wide × 6-7 mm long

Oval-lanceolate, pointed, deflexed, c. 2 mm wide × 4-5 mm long

Fragrance

Sweet but with an acid “rancid” background

Very sweet (like carnations), no “rancid” background

Very sweet

Height

Normally 20-40 cm, can be more

Normally 30-60 cm, but less in dry chalk grassland

Normally 15-25 cm, rarely more

Flowering time

Early June - mid July

Early July - August

Late June - late July

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Plant Crib M easurements are ranges (extremes in brackets) normally found in a population. Vegetative characters (height, leaves, etc.) are very plastic and variable, as is the in florescence density.

a

b

c

Florets of (a) subsp. conopsea, (b) subsp. densiflora, (c) subsp. borealis.

Author

F. Rose, M arch 1988.

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Plant Crib

HELICTOTRICHON / ARRHENATHERUM ELATIUS The similarity in jizz may cause confusion between Helictotrichon species and Arrhenatherum elatius. Arrhenatherum has shorter 7-11mm spikelets (10-28 mm in Helictotrichon), mostly 2-flowered and the lower male, and an awn arising about 1/3 of the way up the lemma (awned at the middle or above in Helictotrichon). Two species of Helictotrichon may also be confused, though they are quite distinct. The lower sheaths of H. pubescens are sometimes very sparsely-hairy, but plants can always be separated from H. pratense in floral and other characters. Helictotrichon pratense (L.) Besser: Leaves stiff, often spiralled, glaucous on upper surface, often flat, entirely glabrous but very rough on upper surface, smooth below; lower sheath glabrous (rarely sparsely hairy); panicle with 1-2 branches at lowest rachis node; spikelets 3-6(-8) flowered. Helictotrichon pubescens (Huds.) Pilg.: Leaves softer, usually hairy, usually folded; lower sheath hairy; panicle with 3-4 branches at lowest rachis node; spikelets 2-3(-4) flowered.

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Plant Crib

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HIRSCHFELDIA INCANA / BRASSICA NIGRA Hirschfeldia incana is widespread as a casual in England and Wales (rare in Ireland and Scotland) and is likely to continue spreading. It is a tall yellow crucifer with appressed fruits which looks remarkably similar to Brassica nigra, and is frequently confused with it, mainly because the ‘veins-on-the-valves’ character used to split them in some keys is very difficult to interpret. Though variable, the plants are quite distinct. The most useful differences are set out below, the different beaks to the fruit being the most diagnostic character.

Fruits of Brassica nigra (a-c) and Hirschfeldia incana (d-g) selected to show variation in shape, size and, (a) strong central vein and weak lateral veins on dried fruit, (b) weak veins in fresh fruit, (c) seeds in fruit (d) shape when immature, (e) weak veins on dried fruit, (f) absence of veins on fresh fruit, (g) seeds in fruit and beak.

Brassica nigra L.

Hirschfeldia incana (L.) Lagr.Foss.

Stem and leaves

Glabrous, glabrescent or sparsely hairy below with coarse hairs

Glabrescent to densely hairy below, glabrous above

Fresh petals

(7-)9-13 mm long

5-10 mm long

Fruits

8-25(-33) mm long (note 1) × (1.5)2-4.5 mm wide

7-16 mm long × 1-1.5(-1.8) mm wide

Valves of fruits

(6-)7-24(-28) mm long, strongly keeled with a rounded prominent central vein and fine weak lateral veins (note 2)

(4-)5-9(-11) mm long, with a very weak central vein, lateral veins absent (note 2)

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Plant Crib Beak of fruits

2-5(-6) mm long, sterile, narrowly conical to linear

3-6.5 mm long, (0-)1(-2) seeded, swollen, tapering to a persistent style c. 1 mm long at tip

Seeds

1.3-2.0 mm, round, grey, brown or black

0.9-1.4 mm long, ovoid to subglobose, brown

Notes 1. M easured from the base of the valve to the tip of the persistent style. 2. M uch more easily observed on ripe, dry fruit. Reference

Rich, T. C. G. (1988). Irish Naturalists’ Journal 22: 531-532.

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Plant Crib HUPERZIA SELAGO SUBSP. SELAGO AND SUBSP. ARCTICA It has been suggested (Flora Europaea 1, 2nd ed. [Tutin et al. 1993], Stace’s New Flora) that the northern Scandinavian taxon H. selago subsp. arctica is present in Scotland. H. selago is, however, a variable species and from our individual field work in Greenland (RWMC) and in Britain and Ireland (ACJ & FJR), forms showing different growth habits may be the result of environmental effects. This is also the opinion of some Scandinavian botanists (e.g. see Engelskjon & Skifte 1995). More comparative study is needed before definitive answers can be given but in the meantime recorders are asked to look at the following characters and mark cards accordingly. The gemmiferous buds (‘bulbils’) are possibly useful characters and material holding them should be collected as voucher specimens (which should be sent to ACJ at the Natural History Museum, Cromwell Road. London SW7 5BD).

H. selago (L.) Bernh. ex Schrank & C. M art. subsp. selago: Shoots often much-branched, and then decumbent in the lower half. Leaves herbaceous when young, becoming coriaceous, lustrous, narrowly triangular to lanceolate, spreading-ascending (in shade) to appressed-ascending (in sun). Gemmiferous branchlets produced in a pseudowhorl at end of annual growth (or throughout season?); gemmae 4-5 mm × 3-4.5 mm, easily detached, lateral leaves (arrowed) 1.5-2 mm wide. H. selago ‘subsp. arctica’ sensu Stace: Shoots branched only at base in tight clusters, erect or decumbent only in lowest 1 cm. Leaves coriaceous even when young, not lustrous, lanceolate to elliptical, usually tightly appressed (even when growing amongst scrubby heather). Gemmiferous branchlets strict or appressed, often hidden in branch leaves, produced more irregularly throughout fertile branch rather than in whorls; gemmae 3-3.5 mm × 3-4 mm, possibly remaining attached for two seasons, lateral leaves 0.5-1 mm wide.

Gemmiferous branchlets of Huperzia selago (a) subsp. selago, (b) ‘subsp. arctica’.

Furthermore the species complex is pan-boreal and elements described from N. America may also be involved. In his extended studies into the genus Huperzia in temperate regions, J. Beitel (pers. comm. 1987) had indicated that some British material of H. selago showed abortive spores and he postulated the possibility of hitherto undescribed taxa in Europe. Unfortunately he did not finish his survey before his untimely death in 1991 but in view of his remarks it is worth checking fruiting material for ‘bad’ spores and reporting any finds. Beitel went on to describe H. appalachiana Beitel & M ickel (subsequently published in Beitel & M ickel 1992) and equated much of the Greenland material to that species. The relationship of that Greenland material to the European material called here H. selago subsp. arctica is not yet clear and the two may be identical. Further study is needed. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib References Beitel, J. M . & M ickel, J. T. (1992). American Fern Journal 82: 45. Engelskjon, T. & Skifte, O. (1995). New records of vascular plants in the Flora of Troms Fylke. Tromura Naturvitenskap 80: 21. Tutin, T. G. et al. (1993). Flora Europaea 1 (edn. 2): 3. Wagner W. H. & Beitel, J. M . (1993). Huperzia. Pp. 20-24 in Flora of North America north of Mexico 2. Oxford University Press, New York. Authors

R. W. M . Corner, A. C. Jermy & F. J. Rumsey, January 1998.

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Plant Crib HYMENOPHYLLUM TUNBRIGENSE AND H. WILSONII The morphology and autecology of the two Hymenophyllum species in the British Isles (H. tunbrigense and H. wilsonii) were studied by Evans (1964 1966) and a detailed Biological Flora account published (Richards & Evans 1972). When growing together, as they do frequently in western Britain and Ireland, H. tunbrigense may be overlooked; it is by far the rarer species. In these cases the two species appear to have ample opportunity to hybridise, as they do in the island of Madeira, but so far no such hybrid has been shown to exist in the British Isles; it should be looked for. It is intermediate in morphology and has a distinctive jizz of a more bushy tunbrigense with a fresh mid-green colour rather than the bluish appearance of that species; its spores are abortive.

Leaf silhouettes of Hymenophyllum (a) H. tunbrigense (b) H. wilsonii.

Hymenophyllum tunbrigense (L.) Sm.

H. wilsonii Hook.

Leaves

Ovate-oblong, blue-green, frequently hanging laxly down over substrate/ neighbouring moss etc. (Fig. a)

Linear, olive-green, arching away from substrate (Fig. b)

Sorus (lipped pocket on leaf margin)

Orbicular, held in plane of leaf; margins of lips (‘indusium’) irregularly toothed

Ovoid, held out from plane of leaf; margins of lips (‘indusium’) entire

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Plant Crib Apex of leaf segment

Truncate to square

Distinctly rounded

Chloroplast size and arrangement

Cells of lamina between veins typically ± square (c. 40-55 µm), with c. 30-40 chloroplasts per cell

Cells of lamina between typically ± rectangular (c. 94 × 40 µm), with c. 6080 chloroplasts per cell

(× 100 or, better, × 400

References

Evans, G. B. (1964). The autecology of Hymenophyllum tunbrigense and H. wilsonii in Britain. PhD thesis, UCNW, Bangor (unpublished). Evans, G. B. (1966). British Fern Gazette, 9: 256-262. Richards, P. W. & Evans, G. B. (1972). Journal of Ecology 60: 245-268.

Authors

A. C. Jermy & J. M. Camus (Fern Guide 1991).

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HYPERICUM A useful account of the British species of Hypericum is given by Robson (1990), including many illustrations. The three main identification problems are given below.

1. Hypericum maculatum Two subspecies of H. maculatum Crantz occur in the British Isles (Robson 1957, 1984, 1990). Subsp. obtusiusculum is widespread in Britain and Ireland, whilst subsp. maculatum is mainly found in west and central Scotland, though occasionally introduced in southern England.

Habit

Subsp. maculatum

Subsp. ob tusiusculum (Tourlet) Hayek

Slender, less branched

M ore stout, more branched

Inflorescence Branches at angle of c. 30° to stem

Branches at angle of c. 50° to stem

Leaves

Usually without pale glands, venation densely reticulate

M ore often with pale glands, venation more lax

Sepals

(1.7-) 2-3 mm wide, tip entire

1.2-2 mm wide, tip eroded

Petals

Entire, margins without dark dots, surface with dark glands mainly in the form of dots

Sometimes crenate; one or two dark dots usually present on margins, surface with dark glands mainly in the form of lines or dashes

Capsule vittae

All longitudinal

Longitudinal and sometimes also lateral, oblique

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Plant Crib 2. Hypericum × desetangsii (H. perforatum × H. maculatum) This hybrid between H. maculatum Crantz and H. perforatum L. is likely to occur where the parents grow in close proximity, but also occurs in the absence of either parent (e.g. Crackles 1990). Its characters are rather vague because the parents appear to be inter-fertile and backcross readily, thus producing a ± continuous range of forms between the parental species. The main characters are: i) the second pair of stem lines in H. maculatum usually disappear in the hybrid, but they may be evident. ii) the leaves usually show characters intermediate between the densely reticulate venation with few or usually no pellucid glands of H. maculatum and the lax reticulate venation with numerous glands of H. perforatum. iii) the sepals are the most useful indicators. The intermediate condition is medium-width sepals with a few superficial dark glands, and the apex of the sepals is obtuse-erose and often apiculate. The whole range between the parents exists, the hybrids always having some denticules (i.e. minor erosions at the tip). H. × desetangsii Lamotte nothosubsp. carinthiacum (A. Fröhl.) N. Robson, recorded from southern Scotland, differs from nothosubsp. desetangsii in the narrower angle of branching, the more densely reticulate leaf-venation, the broader, entire, acute or apiculate sepals and the dark-dotted and darkstreaked (not dark-lined) petals.

Sepals of Hypericum taxa (glands omitted and only main veins drawn; not to scale). (a, b) H. maculatum subsp. maculatum, (c ) H. maculatum subsp. obtusiusculum, (d, e) H. × desetangsii nothosubsp. carinthiacum nothoforma maculatiforme, (f) H. × desetangsii nothosubsp. desetangsii nothoforma perforatiforme, (g-i) H. perforatum.

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Plant Crib 3. Hypericum humifusum / H. linariifolium These species usually remain distinct, but intermediates (hybrids?) occur in south-west England and the Channel Islands. Typical forms can be distinguished by the following characters:H. humifusum L.

H. linariifolium Vahl

Stems

All decumbent to prostrate, internodes with 2 raised lines

At least central stems erect, internodes terete

Leaves

Oblong or lanceolate to obovate, shortly petiolate, with ± numerous pale glands

Linear to narrowly oblong, sessile, without or almost without pale glands

Sepals

Always unequal, apex rounded; margin entire or with a few sessile dark glands, surface with few or no dark glands

Sometimes equal, apex acute to obtuse; margin densely darkglandular-denticulate to darkglandular-fimbriate, surface with ± numerous dark glands

Petals

Only slightly exceeding sepals

M ore than twice as long as sepals

Capsules Only slightly exceeding sepals

About twice as long as sepals

References Crackles, F. E. (1990). Watsonia 18: 63-67. Robson, N. K. B. (1957). Proc. BSBI 2: 237-238. Robson, N. K. B. (1984). Wild Flower Magazine 399: 20. Robson, N. K. B. (1990). British and Irish St John's-worts. In A Guide to some plants. pp. 90-108. Wild Flower Society, London. Author

N. K. B. Robson, June 1997.

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difficult

Plant Crib

IMPATIENS, VEGETATIVE

The leaves of Impatiens species are more variable than noted in Floras, but the species can still be separated vegetatively once c. 50 cm tall (there maybe some difficulty with I. capensis and I. nolitangere). Lower leaves tend to be smaller and have fewer teeth than upper leaves. The number of teeth per cm should be measured at the middle of the leaf on 2-3 leaves for each plant. There should be no difficulty in separating the species in flower (see Stace’s New Flora). There is a map of I. noli-tangere in the Scarce Plants. I. capensis is becoming quite widespread. I. glandulifera Royle 2

1 1

Leav es in whorls of 2-3; mean number of teeth c. 4/cm (range 2-6) (Fig. a) Leav es alternate

2 2

Mean number of teeth c. 3.7/cm (range 2-5) (Fig. b) Mean number of teeth less than 2.5/cm (range 1-3)

3

Mean number of teeth c. 1.5 /cm (range 1-2); leav es rounded to cuneate at base; teeth sharper and deeper (Fig. c)

3

Mean number of teeth c. 2.1/cm (range 1-3).; leav es cordate to cuneate at base; teeth rounder and shallow (Fig. d)

I. parviflora DC. 3 I. capensis M eerb. I. noli-tangere L.

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Plant Crib

Authors

S. Williams & T. C. G. Rich, February 1998. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib ISOETES ECHINOSPORA / I. LACUSTRIS / I. × HICKEYI Isoetes echinospora and I. lacustris appear to have subtle but different ecological preferences, I. lacustris often forming extensive turf in deeper lakes whereas I. echinospora is rarely in such dense patches and is more likely to colonise shallower areas of lakes or pools. Nevertheless they can be found growing in the same lake, and such records are increasing. Whether this is due to more assiduous recording or to the fact that the water level of many lakes in upland Britain is changing because of water storage or abstraction, or to acidification, is uncertain. Where they do grow together they have the potential of hybridising to form I. × hickeyi. So far this hybrid has been found in V.c. 46 (A. O. Chater, pers. comm.) material of which has been cytologically checked to have 2n = 66 chromosomes (D. Britton, pers. comm.), the first confirmed record for the British Isles. Collections made in V.c. 108 conform morphologically but have not yet been cytologically checked. Because of the thick silicious exospore in Isoetes, aborted spores do not collapse but will be seen to vary considerably in size. They often lack the ability to complete partition at the tetrad stage, and clusters of four or, more usually, two spores (appearing ‘dumbell’-shaped) will be seen with a good × 20 hand lens. Both species and hybrid must be confirmed by checking spores.

Isoetes echinospora Durieu

I. × hickeyi W. C.Taylor & Luebke

I. lacustris L.

Habit

Initially erect, but soon bending away from the centre of the rosette, often appressed to the substrate (looking starfish-like), flaccid and clinging together when taken out of the water; scattered though rarely forming continuous swards

Erect or spreading, sometimes recurved, usually remaining stiff when taken out of the water; usually single with parents

Erect, sometimes recurved, somewhat brittle, remaining stiff when taken out of the water; usually present in some quantity, forming a dense turf on deeper lake bottoms

Leaves

3-25 cm long, c. 2.5-3 mm wide near the base, with a perceivably slightly flattened adaxial face, tapering almost immediately from the base to a slender, acute apex

Up to 25 cm long, c. 2.5-10 mm wide, ± cylindrical, tapering in upper one third to a somewhat blunt apex

10-45 cm long, c. 2.5-12 mm wide, ± cylindrical, tapering only slightly in the last few centimetres towards a rather blunt asymmetrical point

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Plant Crib Megaspores

Authors

420-450 µm diameter, densely spiny on all faces (× 20 lens, only seen when dry and mature, i.e. late summer and autumn).

250-500 µm diameter, often linked in twos (dumbellshaped), very variable in one sporangium; wall sculpturing verrucate, or with short spines on obscure ridges, or illdefined.

500-570 µm diameter, the mature spore wall showing anastomosing that resemble braincoral ridges (× 20 lens).

A. C. Jermy & J. M . Camus (Fern Guide 1991), revised A. C. Jermy, December 1997.

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Plant Crib

JUNCUS A useful account of identification of the British and Irish species, including many useful illustrations, is given by T. A. Cope (1990) A guide to British rushes and woodrushes. In: A guide to some difficult plants. Pp 68-89. Wild Flower Society, London. 1. Juncus tenuis / J. dudleyi Juncus dudleyi, best treated as a variety of J. tenuis (see Stace’s New Flora), has been recorded from V.c. 88 and 104, and its current distribution is uncertain and it may be extinct. It is certainly considerably rarer than J. tenuis, which it closely resembles, but could be overlooked. Auricles should be examined on the top 2-3 leaves on flowering stems. The prominent auricles of J. tenuis are sometimes damaged. Juncus tenuis Willd.

Juncus dudleyi Wiegand

Auricles

Scarious, whitish thin, several times as long as wide (Fig. a)

Cartilaginous yellowish-brown, shorter than wide (Fig. b)

Leaves

About as long as stem

About 1/3 length of stem

Habit

Variable

Taller, more stiffly erect

a

b

Auricles (a) J. tenuis, (b) J. dudleyi.

Reference

Richards, P.W. (1943). Journal of Ecology 31: 51-59.

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Plant Crib 2. Juncus bufonius group (J. foliosus, J. ambiguus and J. bufonius) The three British taxa in this group (Cope & Stace 1978) are readily distinguishable in the field from florets and jizz (Figs. a-c) once known - see key in Stace’s New Flora. J. bufonius is by far the commonest throughout the country, occurring in a wide range of habitats. J. foliosus and J. ambiguus are significantly under-recorded. All three species can sometimes be found growing close to each other. J. foliosus is a plant of wet ditches, streams, flushes, pond margins, wet pastures etc., in open vegetation. It is a western plant of the Hiberno-Lusitanian element of the flora. The distinctive bright shining green colour, the striking dark lines down the tepals and conspicuous broad leaves are distinctive, and the ribbed seeds diagnostic. J. ambiguus is more a halophyte but does occur inland in calcareous habitats. It is likely to be confused with or overlooked as J. bufonius, but plants for closer examination can be picked out in the field by the distinctive light brown colour and small clusters of fruits (rather than all flowers spaced out). The best character is the combination of the big blunt fruit and the short blunt inner tepals.

Florets of (a) J. foliosus Desf., (b) J. bufonius L., (c ) J. ambiguus Guss.

Reference

Cope, T. A. & Stace, C. A. (1978). Watsonia 12: 113-120.

Author

T. A. Cope, November 1997.

3. Juncus capitatus / J. pygmaeus / J. bufonius agg. / J. bulbosus On the Lizard in Cornwall, Juncus pygmaeus, J. bufonius agg. and J. bulbosus often grow together in winter-wet hollows and cart tracks (there are two records on the Lizard for J. foliosus and one for J. ambiguus (M argetts & Spurgin, 1991) but the most common Toad rush in these habitats is J. bufonius). J. pygmaeus is diminutive, often under 5 cm. J. bufonius and J. bulbosus may also be diminutive as they become dwarfed and reddened by the habitat in which they grow. As a result, identification is often difficult even in flower. Vegetatively, when compared with J. capitatus and J. bufonius, the PROM INENT auricles of J. pygmaeus are diagnostic (Fig. e). But good auricles are also present on J. bulbosus (Fig. c) and there may be slight auricles on the stem leaves of J. bufonius (Fig. a, b). J. capitatus is usually a plant of low serpentine outcrops, growing around the edges of the rock where there is water seepage. It is often associated with Isoetes hystrix, J. bufonius and Radiola linoides. It may also occur around the margins of winter-wet erosion pans; such pans being marked by the presence of Allium schoenoprasum. Though often only 2-5 cm tall, it is very distinctive. The basal leaves are channelled and there are no auricles to the sheaths (Fig. d). Then there are no stem leaves between the Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib base and the terminal cluster of flowers. Add the presence of two bracts below the cluster (Fig. i), with one much longer than the inflorescence and one has a distinctive ‘jizz’ to the plant.

J. capitatus Wiegel

J. b ufonius agg.

Habit

1-5(-20) cm tall, often turning red in fruit

1.5-35(-50) cm tall, green or brown, sometimes reddish suffused

Leaves

Flattened, not septate, ± channelled

1-5 mm wide, flattened, sometimes inrolled, not septate

Auricles of basal leaves

± Absent (Fig. d)

Rounded to ± absent (stem leaves may have prominent rounded auricles) (Figs. a, b)

Stems

Simple even in large plants; stem leaves absent

Small plants simple and lacking stem leaves, larger plants branched with stem leaves

Inflorescence

Terminal; flowers clustered above 2 leaf-like bracts (Fig. i)

Terminal on small plants, usually with laterals; flowers spaced or clustered

Bracts

Longest bract 4-13 mm long, usually exceeding the inflorescence

Longest bract 2-20 mm long, shorter or longer than the inflorescence, usually shorter than terminal head

Tepals

Outer tepals 3-4.5(-5) mm long, ovate and acuminate, longer than the inner tepals (Fig. h)

Outer tepals 4-7.5 mm long, lanceolate, usually longer than inner tepals (Fig. f)

Bracteole None (Fig. h) s

2 under each flower (Fig. f)

J. pygmaeus is a different matter. In the conditions in which it grows on The Lizard it can show a superficial resemblance to J. bufonius, both having capsules that are shorter than the tepals (Figs. f, j). Readily observed distinguishing characters are given in the Table below. J. bulbosus is readily distinguished by the small tepals and larger capsule projecting above them (Fig. g).

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Plant Crib

a

b

c

d

e

Auricles of (a, b) J. bufonius, (c ) J. bulbosus, (d) J. capitatus, (e) J. pygmaeus.

f

g

h

I

j

Capsules (f) J. bufonius, (g ) J. bulbosus, (h, i) J. capitatus (I = inflorescence), (j) J. pygmaeus.

Juncus pygmaeus Rich. ex Thuill.

Juncus b ufonius agg.

Flowers

M ost borne in clusters of 2 or 3

M ost borne singly

Flower clusters

Not more than 2 clusters per stem

Several individual flowers on each stem, sometimes in clusters of 2 to 3

Inflorescence

Hardly branched, if at all

Branched, occupying at least half of the total height of the plant, with one flower at fork of each division to the inflorescence

Tepals

Tepals of flowers ± equal (Fig. j)

Outer tepals longer than inner ones (Fig. f)

Auricles

Basal leaf sheaths with auricles (Fig. e)

Basal leaf sheaths without auricles (Fig. a)

Colour

Colour change distinctive as habitat dries - plants go pinky-red

Diminutive plants go a deep dark red as habitat dries

J.

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Plant Crib capitatus and J. pygmaeus are both Red Data Book species and full details of all sites are required. J. capitatus occurs on The Lizard, in Anglesey and in the Channel Islands, J. pygmaeus occurs only on The Lizard. Both could occur elsewhere. Reference

Byfield, A. (1993). Notes on the ecology of Juncus capitatus and J. pygmaeus on The Lizard: Unpublished m/s produced for BSBI meeting on The Lizard; 20-22 M ay 1994.

Author

R. J. M urphy & T. C. G. Rich, January 1998.

4. Juncus alpinoarticulatus / J. articulatus Juncus alpinoarticulatus Chaix is a scarce northern montane species of base-rich mires and flushes and always grows in strongly calcareous conditions (Scarce Plants). It seems little-known by many botanists and is likely to be significantly under-recorded. It is most likely to be over-looked as a poorly-growing J. articulatus L., but has a distinctive blunt fruit and inner tepals. The best time to identify J. alpinoarticulatus is late summer when the capsules are mature. Plants are normally more slender than J. articulatus with fewer inflorescences and with branches tending to be erect, parallel to the main axis and less spreading (Fig. a). The capsules are dark, very blunt and rounded, with obtuse tepals (Figs. b-d). Those of J. articulatus are usually acute and trigonous with acute tepals (see the following account). J. articulatus var. nigritellus (D. Don) Druce (see Sell & M urrell 1996) also has slender inflorescences. The inner tepals are always rounded, but the outer ones may be shortly mucronate, sometimes acuminate in continental material (Fig. d). Some montane plants of J. articulatus also have rather blunt capsules but the tepals are more acute giving the inflorescences a more ‘spiky’ appearance. The illustration of J. alpinoarticulatus in S. Ross-Craig Drawings of British Plants is unhelpful.

a

b

c

d

J. alpinoarticulatus (a) inflorescence, (b, c) fruits, Dumfriess, (d) fruit, Alps.

The hybrid between the two (J. × buchenaui Dörfl.) has been reported from V.c. 66, 106 and 108 and has poor fertility. It should be looked for where the parents grow together. Author

R. W. M . Corner, November 1997.

5. Juncus × surrejanus (J. acutiflorus × J. articulatus) Juncus × surrejanus should be looked for whenever its parents grow together. It is probably underrecorded. Note both the hybrid and its parents are variable. Though generally intermediate morphologically, J. × surrejanus shows a very wide variation in all characters; data for the hybrid and both parent species are given below (Blackstock & Roberts 1986). Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Identification can only be tentative until mature inflorescences of all 3 taxa are available at a particular locality. Ripe capsules of J. acutiflorus and J. articulatus protrude well beyond the perianth segments whilst in the hybrid, if capsules are formed, they hardly exceed the perianth segments. Note that they are partially fertile and may produce some seed, it is not consistently sterile as has been reported.

a

b

c

d

e

f

Fruitingcapsules of (a, b) J. articulatus, (c, d) J. x surrejanus (c has one perianth segment removed to show capsule), (e, f) J. acutiflorus.

Juncus articulatus L.

J. × surrejanus Druce ex Stace & Lambinon

J. acutiflorus Ehrh. ex Hoffm.

M ean 3.7, range 2-8

M ean 3.8, range 2-6

M ean 2.7, range 2-4

Appearance of Ribbed, dull, soft leaves and curved, strongly compressed

Smooth, somewhat shining, moderately flexible and often curved, subterete or somewhat compressed

Smooth, shining, stiff and straight, subterete

Length of 2nd leaf from stem apex

M ean 8.8 cm, range 3.0-15.3 cm

M ean 14.0 cm, range 6.2-27.8 cm

M ean 28.7 cm, range 18.0-41.2 cm

No. of heads of flowers per inflorescence

M ean 18, range 3-55

M ean 25, range 2.03.4

M ean 50, range 11102

Perianth segments

M ean 2.6 mm long, range 2.3-3.3 mm

M ean 2.7 mm long, range 2.0-3.4 mm

M ean 2.1 mm long, range 1.5-2.5 mm

Leaves per stem

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Plant Crib Length of inner perianth segment relative to outer

Equal

Generally equal, occasionally slightly longer

Greater

Tips of outer perianth segments

Straight

Often straight, sometimes slightly curved outwards

Curved outwards

Length of ripe capsule relative to perianth

Longer (up to 3.5 mm) and protruding

Very little longer and scarcely protruding

Longer (up to 3.0 mm) and protruding

Colour of ripe capsule

Black and shining

Greenish-brown or brown

Brown

Note data for all characters are based on plants collected from populations in north-western Wales. Reference

Blackstock, T. H. & Roberts, R. H. (1986). Watsonia 16: 55-63.

6. Juncus × diffusus (J. effusus × J. inflexus) J. × diffusus is often confused with sterile or partly-sterile J. inflexus and its precise distribution is unclear but it is probably widespread (Stace 1972). It is sometimes easier to pick out plants intermediate in colour between the stiff, dull, greyish J. inflexus and the softer, shiny, yellowish-green J. effusus from a distance, and these plants can then be investigated in more detail. The following Table is derived from Crackles (1987):

Juncus effusus L.

Juncus × diffusus Hoppe

Juncus inflexus L.

Stem

Green, soft, pliable, polished, smooth when fresh with 40-90 striae; pith continuous

Pale green, firm, fairly stiff, dull, slightly grooved 18-45 ridges; pith usually continuous

Grey-green glaucous, firm and stiff, dull, with 12-18 prominent ridges; pith interrupted

Inflorescence

Branches many, short, tawny in fruit when fresh

Branches long, fawn in fruit when fresh

Branches few, long, dark brown in fruit when fresh

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Plant Crib Perianth segment s

Lanceolate-acute; equal

Lanceolate, some tips subulate; unequal

Narrowly lanceolate, tips subulate; unequal

Capsule

Equalling perianth; chestnut in colour; usually fertile

Undeveloped or shorter than the perianth; variably fertile, often sterile

Longer than perianth; dark brown; fertile (sometimes sterile)

References Crackles, F. E. (1987). Yorkshire Naturalists’ Union Bulletin 8: 12-13. Stace, C. A. (1972). Watsonia 9: 1-11.

7. Juncus × kern-reichgeltii (J. effusus × J. conglomeratus) Juncus × kern-reichgeltii Jansen & Wacht. ex Reichg. is difficult to identify as the parents are similar to each other and are both variable, and many of the records are probably errors. It is likely that hybrids are rare (cf. Stace 1972) but they do occur. The best character is the intermediate ridging of the stems and degree of in-rolling shown by the base of the main bract (see Table on page 333). In the field the stems of J. effusus are usually smooth when rolled between the lips, but the ridges become more apparent as they dry. The hybrids are apparently fertile (Sell & M urrell 1996) and are often easier to determine in the field where all the variation can be assessed, rather than in the herbarium. They may occur more frequently at altitude where the flowering times overlap more. It is as well to be aware of the infraspecific taxa before assuming odd plants are hybrids (after Sell & M urrell 1996): J. effusus L. var. effusus: Inflorescence lax, with suberect to widely divergent branches. var. subglomeratus DC. (var. compactus Lej. & Courtois): Inflorescence condensed into a compact, rounded head. J. conglomeratus L. var. conglomeratus: Inflorescence a compact, rounded head. var. subbuliflorus (Drejer) Asch. & Graebn.: Inflorescence of several stalked heads. There is also an unnamed variant with lax heads (material in BM). References Agnew, A. D. Q. (1968). Watsonia 6: 377-388. Stace, C. A. (1972). Watsonia 9: 1-11.

8. Juncus compressus / J. gerardii Juncus compressus Jacq. and J. gerardii Loisel. can be separated using the characters in Stace’s New Flora, but it is worth drawing attention to the occasional occurrence of J. compressus in brackish sites, and the occasional occurrence of J. gerardii inland in non-saline areas.

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Plant Crib Juncus effusus L.

Juncus conglomeratus L.

Stem sheathing scales

Black to red-brown at base

Red-brown to olive at base

Stem-ridges at inflorescence

30-60 when dry, smooth when fresh

15-24

Spathe-length

Usually 15-30 cm but variable

Usually 5-15 cm but variable

Bract of second cyme

Not as long, or as long as, split in spathe

Longer than split in spathe

Inflorescence

Diffuse or compact

Almost invariably compacted into globose head

Perianth

Outer whorl of three segments about 0.5 mm longer than inner whorl; perianth segments olive with green or light brown centres

Outer whorl as long as inner whorl; perianth segments with dark red-brown edges, lighter centres

Stamens

Anthers oval, shorter than filaments

Anthers strap-shaped, longer than filaments

Style

Very short or absent

One third as long as ovary

Fruit apex

Retuse or truncate, not apiculate

Truncate, apiculate

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Plant Crib

LABURNUM Laburnum taxa are sometimes planted in hedges, but rarely appear self-sown. Recent studies have shown that there may be three taxa involved which can be distinguished using the Table and illustrations below. The hedge plants in Wales are the hybrid (L. × watereri) and a large-flowered cultivar of L. anagyroides; the hybrid flowers about three weeks later. In the hybrid, both the legumes and leaves tend to lose their hairs as the season progresses. Also in the hybrid, the ovary usually remains glabrous until well after the petals have fallen, the often quite dense hairs on the legume developing at a surprisingly late stage.

L. anagyroides

L. × watereri

L. alpinum

Lower surface of leaflet and TS of upper suture of legume

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Plant Crib L. anagyroides of Welsh hedges

L. × watereri of Welsh hedges

L. alpinum (note 1)

Young shoot apices and rachis of racemes

White-sericeous

Subglabrous, green

Subglabrous, green

Lower surface of leaflets

Densely appressedhairy, with abundant short hairs 0.1-0.3 mm and sparse long hairs 0.4-0.7 mm

Without short hairs, and with only the sparse long hairs 0.40.7 mm (occasionally glabrous)

Glabrous except on veins (occasionally with very sparse long hairs 0.4-0.7 mm near margins or when young)

Corolla

22-23 mm (see note 1)

18-21 mm (see note 2)

14-17(-18) mm

Dark markings inside standard

Reaching at least ½ way up

Reaching not more than 1/3 of way up

Reaching not more than 1/3 of way up, or absent

Legume

Appressed-hairy, with Subglabrous or thick, rigid, appressed-hairy, with coriaceous walls thin but scarcely flexible walls

Glabrous at least when mature, with thin, flexible walls

Upper suture of legume in section

Broad and truncate

Acute, or with a keel up to 1 mm high

With a conspicuous wing c. 2 mm high

Seeds

(1-)2-4(-6)/pod

1-2(-3)/pod

1-5/pod

Notes 1. Wild continental material, material in Leicester gardens, and all material in K and BM have corollas 17-20 mm and seeds (1-)4-8(-9). 2. Herbarium material of garden origin at K and BM has corollas (14-)15-18 mm. Author

A. O. Chater, December 1997.

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Plant Crib

LAKE-BOTTOM ‘ISOETIDS’ WITH TERETE LEAVES: ERIOCAULON / ISOETES / LITTORELLA / LOBELIA / SUBULARIA, VEGETATIVE The latter four of these taxa with terete leaves are widespread and relatively frequent in clear lakes, lochs, etc. They look superficially similar vegetatively, but can easily be distinguished even from solitary leaves washed up on the shore. Note the characters given below are diagnostic only for these taxa. With practice, growth, form, colour etc. are also useful. For Luronium and Baldellia which have flat leaves, see page 313. The Red Data Book species Eriocaulon aquaticum is easily distinguished from all by the segmented roots, which are very obvious. Under water, its narrowly triangular rosettes are also distinctive. Isoetes roots are brownish, the other species are white. Isoetes spp.

Lob elia dortmanna

Littorella uniflora

Sub ularia aquatica

± Round with 4 hollow tubes

Compressed with 2 hollow tubes

± Round, spongy ± Round to inside triangular, solid

Leaves

Flattened and expanded at base, generally tapering gradually to point or terete and tapering in upper ¼ only

Strap-shaped, apex blunt and curving out; small quantity of milky latex exudes when leaves broken off

Cylindrical, narrowing suddenly at apex, variable in length

Expanded at base, tapering gradually to a fine point

Habit

Solitary

Solitary

Stoloniferous

Solitary

Cross section at middle of leaf

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LEERSIA ORYZOIDES / PHALARIS ARUNDINACEA, VEGETATIVE Leersia oryzoides (L.) Sw. and Phalaris arundinacea L. may grow together at the edge of water by ditches, canals and ponds. Where vegetative plants (c. 25 cm - 40 cm high, in late June - late July) are intermingled they can look superficially very alike with the same yellow-green colour and similar leafshape. The easiest way to tell them apart is by ‘feel’ - but Leersia is not called ‘Cut Grass’ for nothing! When fingers are run gently up the stems, the upper sheaths of Leersia have short, bristly, reflexed hairs between the ribs, and the rough leaf blades have spiny margins. Leersia is also hairy at the nodes.

Typical angles of leaves in Leersia. (Note some inflorescences beginning to open).

As the grasses grow taller, Leersia can be picked out by the angle of the leaf above the top sheath; this is held at a very characteristic angle of about 110° from the sheath (see illustration) and by August the top sheath often shows a distinct bulge where the panicle is developing inside the rolled sheath. In most years the panicles are not fully exserted or not exserted at all, in which case the spikelets are cleistogamous and the grains can mature inside the sheath. The panicles open freely only when there is both a warm spring and hot sunny weather in late summer. These are the years in which searches are likely to be most successful, and they have occurred about once in every 8-10 years over the last 50 years. Leersia is now thought to be very rare but is easily over-looked. Full population details should be recorded for all sites. Author

M . Briggs, November 1997.

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LEMNA 1. Lemna gibba / L. minor Under favourable conditions there should be little difficulty distinguishing L. gibba fronds with their characteristic swollen bases from the flat fronds of L. minor. In fruit the species are easily distinguished: L. gibba has 2-6 ovules and a winged fruit with 2 seeds, L. minor 1 ovule and an unwinged fruit with 1 seed - but who ever looks for or finds fruit? In unfavourable conditions (i.e. stagnant, nutrient-poor or cold water), the swollen base of L. gibba may not develop and the fronds are flat; these are easily confused with L. minor. As the two species usually grow together (conveniently for comparison), L. gibba fronds can usually be distinguished using a combination of characters below. Note, there may be different clones of the same species present at any one site which look slightly different. On a world-wide basis there are considerable problems separating the two species (Landolt 1975, Kandeler 1975). It may not be possible to name some plants.

Lemna gib b a L.

Lemna minor L.

Size

Generally larger (3-)3.5-6 mm

Generally smaller (2-)3-5 mm

Shape

Rounder; length:width ratio c. 1-1.5

M ore ovate, length:width ratio c. 1.2-2.0

Veins (note 1)

(3-)4-5, separate from base (Fig. a)

3(-5), when 4 or 5, the outermost connected to the inner some distance from the base (Fig. b)

Lower surface

Gibbous to flat, often with relatively few distinct large cells in the middle and smaller ones outside

Flat, with many indistinct small cells of similar size over the surface

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Plant Crib Note

1. See L. minuta / L. minor account

a

b

Fronds of (a) L. gibba, (b) L. minor, showing general shape and positioning of veins.

References Kandeler, R. (1975). Aquatic Botany 1: 365-376. Landolt, E. (1975). Aquatic Botany 1: 345-363.

2. Lemna minuta (L. minuscula) / L. minor L. minuta is now widespread in S Britain and is continuing to spread. It has also reached Ireland. Some authors consider it more frost resistant and therefore easier to detect in winter but confirmation of this is required. Plants can be very difficult to identify with confidence in winter The number of veins is the most reliable character, but is not easy to see in the field (Leslie & Walters 1983). The solitary vein of L. minuta is difficult to detect in the field but veins can sometimes be seen in decaying fronds. With practice, it is possible to see the veins in L. minor by holding the frond so that the light is transmitted through it but so the face of the frond is not at right angles to the source. In difficult cases, fronds should be boiled in lactophenol for 30 seconds, after which they become colourless and translucent. The other characters below enable plants to be named reasonably reliably with practice. Though L. minuta is usually smaller than L. minor, there is overlap in size and occasional populations of L. minor with uniformly small fronds may be found.

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Plant Crib Lemna. minuta Kunth

Lemna minor L.

Veins

0-1

3(-5)

Frond size

1-3 mm

(2-)3-5 mm

Frond colour

Pale green, dull

Dark green, shining

Frond shape

Usually elliptic, symmetrical

Usually obovate, asymmetrical

Frond apex

Obtuse, usually with slight point

Rounded, usually without a point

Upper surface of frond

Very shallowly ridged, visible to the naked eye

Flat or smoothly rounded

Reference

Leslie, A. C. & Walters, S. M . (1983). Watsonia 14: 243-248.

3. Lemna turionifera This species is spreading in central Europe and could appear in Britain. It looks like an olive-green form of L. minor or L. gibba flushed with red pigmentation (remember Spirodela polyrhiza is red underneath but has many roots) and can be separated as follows (Landolt 1980): L. turionifera Landolt: Fronds with prominent papules (i.e. little ‘bumps’) of ± equal size above the midline on the upper side (visible to naked eye but clearer with a ×10 lens); very often red-coloured underneath; in unfavourable conditions forming small obovate to circular, rootless, dark green to brown turions. L. minor L. and L. gibba L.: Fronds without prominent papules (one or two very small ones sometimes present); rarely reddish coloured underneath; fronds rarely forming turions, and if present, turions have short roots. Reference

Landolt, E. (1980). Biosystematic investigations in the family of duckweeds (Lemnaceae), 1. Veröffentlichungen des Geobotanischen Instituts der Eidg. Techn. Hochschule, Stiftung Rübel, in Zürich 70. 247 pp.

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Plant Crib

LIMONIUM VULGARE / L. HUMILE Difficulty arises in separating these two species most often at sites where they grow together. A wide range of morphological forms with varying degrees of intermediacy may be found alongside typical examples of both species. This variability is not environmentally determined as once thought; hybridisation and subsequent introgression account for a substantial part of it (Dawson & Ingrouille 1995). There are a number of morphological characters which may be used to distinguish the two species, although there is overlap and no one character can be used (see Stace’s New Flora). Spike length is a debatable character; in east coast and Solent forms of L. humile M ill., spike length is plainly longer than in L. vulgare M ill., but taximetric analysis of 'pure' forms of L. humile from Ireland and W Wales show it is similar to L. vulgare. There are no significant differences between species concerning branching above or below the middle of the stem. Confirmation of identification can only be obtained by microscopic examination of pollen and stigmas, which does require some experience due to wider range of variation than previously recognised (cf. Dawson & Ingrouille 1995). In L. vulgare there is a dimorphy of pollen and stigmas, "B+Pap" forms having a papillate stigma associated with B type pollen (see diagram). "A+Cob" forms have longer cob styles and A type pollen (if flowers are seen with long-exserted styles they are almost certainly "A+Cob" morphs of L. vulgare). L. humile has an "A+Pap" morph combination.

Pollen and stigmas of dimorphic Limonium. The two pollen types, A & B, are shown, diameter c. 60 µ m, and the two stigma types, diameter c. 100 µ m (after H. G. Baker).

Reference

Dawson, H. J. & Ingrouille, M . J. (1995). Watsonia 20: 239-254.

Author

H. J. Dawson, February 1988, updated T. C. G. Rich, 1997.

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LIPARIS LOESELII (L.) RICH. The two varieties of this protected species are easily distinguished by leaf shape and habitat, and are almost distinct species. As a UK Biodiversity ‘short list’ species it is of high interest, and full details should be recorded of all populations. Var. loeselii: Leaves oblong-elliptic; up to 12 flowers. Fens and reed swamp, mainly East Anglia. Var. ovata Ridd. ex Godfery: Leaves ovate to broadly elliptical; flowers up to 6(-10) flowers. Dune slacks, mainly W Britain.

a

b

Leaf shapes. (a) var. loeselii, (b) var. ovata.

Author

F. Rose, October 1997.

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Plant Crib

LURONIUM NATANS / BALDELLIA RANUNCULOIDES / ALISMA Although the stronghold of the statutorily protected species Luronium natans (L.) Raf. is Wales and the Welsh borders (Scarce Plants), it has been found recently in Cumbria, Scotland and Ireland where it is probably an over-looked native rather than a recent arrival; it may well be more widespread still. Full details of all sites should be recorded. Specimens should only be taken, preferably under license, to confirm identification at new sites. Luronium is under-recorded due to its generally submerged aquatic habitat, shy flowering, great phenotypic plasticity (many floras account do not adequately cover the range of variation) and similarity to other aquatic plants. The leaves do not tend to be caught on grapnels or get washed ashore and often the easiest way to find it in water is to dive or use a long hooked pole. It may also be found easily when exposed in seasonal ponds. The species can grow in both isolated clumps or extensive lawns on the bottom of canals, lochs, ponds, etc., in water up to 4 m depth in clear lakes. In flower when exposed or in shallow water, Luronium is unlikely to be mistaken for other species. The flowers are usually in groups of 1-5, about 12-18 mm in diameter, often floating on the surface of the water, with white petals with a yellow base. Cleistogamous flowers are a common feature of many British canal and lake populations, especially where the plants are poorly illuminated. Submerged plants are distinct from isoetids with terete leaves (cf. page 382) due to the flat, translucent leaves and ready development of stolons (they look rather like the indoor ‘spider plant’ except that they have flat leaves). In still or gently flowing water the submerged rosette leaves are typically c. 5-15 cm long, strongly flattened, linear-triangular, tapering uniformly from a base c. 4-7 mm wide to a fine acute tip (not obtuse). They are pale green and translucent with a thicker, greener, midrib occupying about the central half of the leaf (most noticeable when fresh). In flowing water, submerged leaves may be parallelsided, up to 50-60 cm long, c. 5-8 mm wide and appear very different to those of still-water plants; these leaves resemble those of Sparganium but snap easily when bent double and have an acute rather than acuminate apex. Runners/stolons from the base of the rosettes are about 1 mm in diameter and up to c. 20 cm long, and they may be green or white (Figs. a, b). The stolons develop small tufts of leaves at regular intervals along their length even when they are not rooted in the substratum. The aerial or floating leaves when present can vary markedly between populations (Fig. e). In deep water, leaves may float on the surface with very slender petioles up to twice the depth of water. The blades are typically 1-4 cm long, obovate, elliptic or lanceolate, with a retuse to obtuse apex. When plants are exposed or in very shallow water, the leaves are similar but may be held erect (like Baldellia or Alisma) and maybe acute at the apex (NB the latter will key out incorrectly in Stace’s New Flora). They have a distinct venation of a central vein and one strong lateral vein on either side of the midrib, with smaller cross-connecting veins between. When floating, at first glance they look like those of Potamogeton gramineus. Luronium is very similar vegetatively to Baldellia ranunculoides (L.) Parl. which has similar submerged leaves, though these are less flattened and often slightly widened at the apex, and the aerial or floating Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib leaves are usually acute and lanceolate. Baldellia may sometimes develop stolons, or the flowering stems may trail and produce roots and tufts of leaves (especially late in the season). It is unclear to which of these two forms the name B. ranunculoides var. repens Davies has been applied, but plants of the latter form are sold under this name in garden centres. Depauperate Baldellia plants may only have one or two flowers. A very useful character is that when fresh, crushed Baldellia leaves also smell quite distinctly and strongly of Cumin/Coriander (absent in Luronium but sometimes present weakly in Alisma) (N. Willby, pers. comm. 1994). Sterile, linear-leaved Luronium could also be confused with young Alisma plantago-aquatica / A. lanceolatum plants, which however do not produce stolons and generally have more acute floating leaf apices (Fig. i.). Alisma can develop linear underwater leaves like those of Luronium when they first germinate and possibly in deeper water, but in the latter case almost always have the typical large leaves present. Both can have ± parallel sided floating leaves, though the leaf apex of Alisma tends to be more acute and Luronium obtuse. It is not yet possible to name seedlings. Key to vegetative Luronium / Baldellia / Alisma (excluding A. gramineum) 1 1

Stolons present (see note 1), or plants creeping and rooting at the nodes (Figs a, b, d, f ) Stolons absent, and not creeping or rooting at the nodes (Figs. c, g, h, i)

2 5

2 2

Floating/aerial leav es absent (Figs. b, f ) (see note 2) Floating/aerial leav es present (Figs a, d)

3 4

3 3

Submerged leav es sword-shaped, ± parallel f or much of their length and tapering to a fine tip (Figs. a, b)Luronium Submerged leav es distinctly widened towards apex before tapering to a f ine tip (Figs. f, g) Baldellia

4 4

Crushed leaves not smelling noticeably; plant truly stoloniferous (Fig d) Luronium Crushed leaves smelling strong of Cumin/Coriander; inf lorescence developing roots and tufts of leav esBaldellia

5 5

Crushed leaves smelling strong of Cumin/Coriander, attenuate at the base Crushed leaves not smelling noticeably, cordate to attenuate at the base

Baldellia

Luronium /Alisma plantago-aquatica /A. lanceolatum (flowers/fruits required) Notes 1. Stolons are put out from the base of the plant and will be obvious when above the substrate, but may be hidden in the sediment especially in soft mud; it may be necessary to excavate some plants (extensive ‘lawns’ of plants are generally indicative of stolons). Stolons are usually absent in winter. 2. Submerged leaves are not differentiated into a distinct petiole and blade but are flattened, thin, ± translucent with an obvious central vein. Floating/aerial leaves are clearly differentiated into a distinct petiole and blade, are thicker and opaque. Plants may or may not have some leaves transitional between the two forms.

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Plant Crib

Luronium natans (a) plant with submerged rosettes, stolons, floating leaves and flowers, (b) submerged rosettes and stolons only, (c ) no stolons, (d) aerial leaves, flowers and stolons (no submerged leaves), (e) variation in floating leaves. Baldellia ranunculoides (f) stolons and submerged leaves, (g) submerged leaves and flowers, (h) aerial leaves and flowers. Alisma-plantago-aquatica (I) seedling with submerged leaves and young floating leaves (silhouettes del. S. Williams & T. C. G. Rich).

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Plant Crib References Rich, T. C. G., Kay, G. M . & Kirschner, J. (1995). Irish Naturalists’ Journal 25: 140145. Willby, N. J. & Eaton, J. W. (1993). Journal of Aquatic Plant Management 31: 7076. Authors

R. A. Jones & T. C. G. Rich, February 199

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Plant Crib

LUZULA 1. Luzula × borreri (L. forsteri × L. pilosa) Luzula × borreri is not uncommon in areas where its parents grow together in southern Britain, but is probably under-recorded. The Irish record for the hybrid (Ebinger 1962, Synnott 1973) is L. pilosa. The hybrid is similar to L. pilosa in general appearance (i.e. leaf width and arrangement of the inflorescence) but it may be robust with hybrid vigour and it is usually ± sterile and produces few seeds. Look for plants with few or no capsules developing (NB L. pilosa tends to produce a series of inflorescences so the youngest may not have had time to produce ripe fruits).

a

b

c

Fruiting capsules. (a) L. pilosa, (b) L. × borreri, one perianth segment removed to show capsule, (c ) L. forsteri.

The parents are quite distinct, though sometimes confused. Characters found to be of little use in distinguishing them include the presence of a mucro at the leaf tip, anther size and ratio of anthers to the filaments. The following Table has been compiled from Ebinger (1962), CTM and from specimens in CGE and NMW.

d

e

Seeds. (d) L. pilosa, (e) L. forsteri.

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Plant Crib Luzula pilosa (L.) Willd.

Luzula × b orreri Bromf. ex Bab.

Luzula forsteri (Sm.) DC.

Broadest basal leaf width

Up to 10 mm

Up to 5 mm

Up to 4 mm

Stem leaf length

Less than 4 cm

2-5 cm

Usually more than (2.5-) 3 cm

Pedicels in flower

Spreading-deflexed

Spreading

Spreading or drooping to one side

Pedicels in fruit

Spreading-deflexed

Variable but tending to spread

Erect (to slightly spreading)

Perianth segments

Shorter than or equalling capsule

M uch longer than capsule if one develops

Equalling or longer than capsule

Capsules

Wide at base, narrowing abruptly from below middle to truncate apex (Fig. a); usually 3 seeded

Absent or poorly developed (Fig. b); sterile or 1(-2) seeded

Ovoid, apex acuminate (Fig. c); usually 3 seeded

Seeds

c. 1.5 × as long as wide; appendage usually more than 0.6 mm long, hooked (Fig. d)

Shrivelled or similar to L. pilosa

c. 2 × as long as wide; appendage usually less than 0.6 mm, ± straight (Fig. e)

References Ebinger, J. E. (1962). Watsonia 5: 251-254. Synnott, D. (1973). Irish Naturalists’ Journal 17: 327-330. 2. Luzula pilosa / L. sylvatica vegetative Those pondering if a vegetative Luzula is L. pilosa (L.) Willd. or young L. sylvatica (Huds.) Gaudin can examine the leaves; L. pilosa has leaves which are widest near the middle and taper to a narrow base, whilst L. sylvatica has leaves ± widest and ± sheathing at the base. There should be no difficulty with mature L. sylvatica.

L. sylvatica

L. pilosa

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Plant Crib 3. Luzula campestris / L. multiflora group / L. pallidula L. campestris and L. pallidula are distinct taxa which should cause few identification problems. The patch-forming L. campestris is conspicuous in spring and early summer, but the leaves tend to die down in mid summer when it is over-looked, and re-appear in the autumn. L. pallidula is distinctly small and slender, and the tiny seeds and papillose peduncles should distinguish it if the small, light brown florets (tepals 1.5-2.8 mm) are not obvious enough. Pale-flowered forms of L. multiflora are not rare in shady places and are regularly misinterpreted as L. pallidula. The main difficulty will be separating L. multiflora and L. congesta in the L. multiflora group. M any populations of L. congesta have plants with pedunculate clusters of flowers, and have been widely over-recorded as L. multiflora. Some hybrids occur within the group but need a chromosome count for verification and are unlikely to be picked out except by the expert. Taxonomic ranks within the L. multiflora group are down to personal preference, and L. congesta can be recorded as a species (cf. Buchanan 1960; Kirschner & Rich 1993, 1996; Armstrong 1997) or subspecies (cf. Stace 1997) as long as the taxon within the L. multiflora group is made clear. Historical records of these taxa (including those for the M onitoring Scheme) need to be checked against herbarium material as they have for so long been misinterpreted in Britain. We do not currently accept L. multiflora subsp. frigida in Scotland (cf. Sell & M urrell 1997; see Kirschner 1993); the material on which this was based was examined by us in CGE and represents L. multiflora. However, the taxon should be looked for in Scotland. The taxa of the L. multiflora group form a polyploid series of increasing size. They are variable and differ in a series of quantitative overlapping characters, and there is little option but to measure plants with a graduated lens to identify them. Ecotypic variation is often complicated by considerable phenotypic plasticity, and the taxa need to be confirmed using a combination of characters. The taxa are less discrete and show considerably more variation in the British Isles as a whole than as reported for NW England by Armstrong (1997). Her lists of characters for distinguishing selected pairs of taxa are generally useful, excluding stalked/congested inflorescence characters. The best characters are seed shape and size, anther/filament ratio, style length and presence of creeping rhizomes and/or stolons. Ripe brown seeds should be measured flat side down to their full length, ignoring the appendage (unripe or shrunken/wrinkled seeds should be ignored). Style measurements exclude the stigmas. Specimens for identification should include rootstock, lower leaves and ripe seed. Small-flowered plants from Ireland and Scottish mountain plants are especially welcome. 1 1

2 2

Plants f orming patches with creeping stolons and rhizomes; seeds (ignoring appendage) ± globular (Fig. e); anthers usually more than 3 times as long as f ilaments (Fig. h) L. campestris Plants tuf ted, rhizome short, oblique or v ertical; seeds ov oid to oblong-ov oid (Figs. a-d); anthers usually less than 2.5 times as long as filaments (Figs. f -g) 2 Peduncles densely papillose throughout (microscope, in silhouette); outer and inner tepals conspicuously unequal (Fig. i); seeds 0.5-0.6 mm wide L. pallidula Peduncles smooth or sparsely papillose below the f lower clusters; outer and inner tepals equal or outer tepals slightly longer by 0.2-0.4(-0.6) mm (Figs. j-k); seeds 0.7 mm or more wide 3

3

Seeds (excluding appendage) 1.2-1.5 mm long (Fig. d); inf lorescence usually congested or sometimes pedunculate

3

Seeds (excluding appendage) to 1.1(-1.2) mm long (Figs. b-c); inf lorescence usually pedunculate

L. congesta 4

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Plant Crib 4 4

Peduncles erect, usually straight; seed appendages 0.4-0.5 mm long; basal leav es usually > 3 mm wide; capsule segments 2.0-2.8 mm long L. multiflora subsp. multiflora Some peduncles recurv ed, others of ten f lexuose; seed appendages 0.2-0.3 mm long; basal leav es usually less than 3 mm wide; capsule segments 1.9-2.2 mm long L. multiflora subsp. hibernica

Seeds. (a) Luzula pallidula, (b) L. multiflora subsp. hibernica, (c ) L. multiflora subsp. multiflora, (d) L. congesta, (e) L. campestris.

f

g

h

Anthers and filaments. (f-g) L. multiflora group, (h) L. campestris.

i

j

k

Capsules. (i) unequal tepals (Luzula pallidula), (j) nearly equal tepals (L. congesta, L. multiflora subsp. hibernica), (k) ± equal tepals (L. campestris, L. multiflora subsp. multiflora).

Descriptions of taxa (after Kirschner & Rich 1993, 1996) L. pallidula Kirschner (L. pallescens auct.): Densely caespitose, rhizome very short. Peduncles erect, densely papillose (microscope), often with secondary branches. Outer perianth segments 2.0-2.8 mm long, conspicuously longer than the inner. Anthers usually as long as the filaments. Styles 0.2-0.3 mm long. Seeds ovoid, 0.7-0.8 mm long (excluding appendages) × 0.5-0.6 mm wide, appendages 0.20.3 mm long. Diploid. On track sides, open woodland and disturbed open boggy or sandy vegetation, and could be over-looked as it is an annual-biennial flowering in M ay and June, and disappearing by mid summer. It is a very rare plant still present in V.c. 31, but extinct in Ireland Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib (Kirschner & Rich 1993; Rich 1994) (a tentative V.c. 54 record in E. J. Gibbons Flora of Lincolnshire is L. multiflora). L. multiflora (Ehrh.) Lej. subsp. hibernica Kirschner & T. C. G. Rich: Usually densely caespitose, without stolons. Peduncles usually flexuose and with at least one in an inflorescence recurved, smooth. Perianth segments of ± equal length or the outer to 0.6 mm longer, 2.6-3.2 mm long. Anthers as long as or just than filaments. Styles 0.6-0.7 mm long. Seeds oblong-ovoid, 0.8-0.9 (-1.0) mm long × usually 0.7 mm wide, appendages 0.2-0.3 mm long. Tetraploid. Probably widespread in Ireland. L. multiflora (Ehrh.) Lej. subsp. multiflora: Usually densely caespitose, without stolons. Peduncles erect, smooth. Perianth segments of equal length, 2.8-3.5 mm long. Anthers as long as or up to two times the filaments. Styles 0.4-0.9 mm long. Seeds oblong-ovoid, 0.9-1.1(-1.2) mm long × usually 0.8 mm wide, appendages 0.4 mm long. Hexaploid in Britain. Widespread in Britain often on mineral-rich soils and in meadows. L. congesta (Thuill.) Lej.: Plants densely caespitose without stolons, rhizome vertical, of medium length. Inflorescence congested, some of the clusters may be pedunculate, peduncles erect, smooth. Perianth segments of ± equal length, 2.8-3.8 mm long. Anthers as long as the filaments. Styles 0.5-0.8 mm long. Seeds ovoid, 1.2-1.5 mm long × 0.9-1.0 mm wide, appendages 0.4-0.6 mm long. Octoploid. Possibly the commonest taxon in the L. multiflora group, widespread in Britain and Ireland often on peaty soils. L. campestris (L.) DC.: Laxly caespitose, rhizome long, creeping, short stolons often present. Peduncles smooth, some of them recurved. Perianth segments of equal length, 2.8-4.1 mm long. Anthers usually 3-6 times as long as filaments. Styles 0.9-1.6 mm long. Seeds almost globular, 1.01.1 mm long × 0.9-1.0 mm wide, appendages 0.4 mm-0.7 mm long. Diploid. Common and widespread. References Armstrong, J. (1997). Watsonia 21: 259-270. Buchanan, J. (1960). Proceedings of the Linnean Society of London 171: 126-128. Kirschner, J. (1993). Folia Geobotanica Phytotaxonomica 28: 141-182. Kirschner, J. & Rich, T. C. G. (1993). Irish Naturalists’ Journal 24: 297-298. Kirschner, J. & Rich, T. C. G. (1996). Watsonia 21: 89-97. Rich, T. C. G. (1994). Irish Botanical News 4: 26-28. Authors

J. Kirschner & T.C.G. Rich, 1997.

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Plant Crib

MEDICAGO, VEGETATIVE KEY TO WIDESPREAD ANNUALS The following key and illustrations may help identify the more widespread native annual Medicago species. M aps of M. minima and M. polymorpha are given in the Scarce Plants.

Leaflets and stipules of (a) M. arabica, (b) M. polymorpha, (c ) M. lupulina, (d) M. minima. 1 1 2 2

Leaf lets with a dark blotch (Fig. a) M. arabica (L.) Huds. Leaf lets unmarked 2 Stipules laciniate, only attached to petiole at base (Fig. b); plant ± glabrous M. polymorpha L. Stipules toothed to entire, attached to petiole for more than half length; plant sparsely to densely hairy

3 3 3

Leaf lets usually more than 6 mm; stipules half cordate, ± toothed (Fig. c) Leaf lets less than 6 mm; stipules lanceolate to ovate, ± entire to toothed (Fig. d)

M. lupulina L.

M. minima (L.) Bartal. Reference

Walls, R. M . (1994). Recording Dorset 4: 14.

Author

R. M . Walls & T.C.G. Rich, November 1997.

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MEDICAGO LUPULINA / TRIFOLIUM DUBIUM Vegetatively, these two species can be distinguished as follows: Medicago lupulina L.: Usually densely hairy, with leaflets which are toothed on the margins and entire to emarginate at the apex but with a small distinct point in the middle; stipule often with small, obtuse teeth. Trifolium dubium Sibth.: Sparsely hairy to glabrous and has leaflets which are toothed on the margins and entire to emarginate at the apex; stipule entire.

Medicago lupulina

Trifolium dubium

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MUSCARI The illustrations and notes can be used in conjunction with the key in Stace’s New Flora to help identify the following three similar species (M. comosum (L.) Mill., Tassel hyacinth, is obviously different to these with its erect tassels of upper flowers). M. armeniacum Leichtlin ex Baker (Fig a) has lighter blue flowers than M. neglectum, and they become paler as they age (these are drawn a little dark). The flowers are scentless to most people. M. botryoides (L.) Mill. (Fig. b) has a more globose perianth, scentless flowers, strongly recurved perianth teeth, two subtending bracteoles and broad short leaves. M. neglectum Guss. ex Ten. (Fig. c) has deep blue flowers which turn blue-black as they age, and has a curious smell, supposedly of starch.

Muscari. (a) M. armeniacum, (b) M. botryoides, (c ) M. neglectum.

a Author

b

c

G. M. S. Easy, January 1998.

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NITELLA FLEXILIS / N. OPACA Wood & Imahori (1965) united Nitella flexilis and N. opaca, which had been regarded as separate species for over a century. This view was followed by M oore (1986) (under N. flexilis var. flexilis) and Stewart & Church (1992) (under N. flexilis). However, in line with the prevailing view elsewhere in Europe it is necessary to reinstate them as two species. There are illustrations on page 2. The essential difference is that N. flexilis is monoecious and N. opaca dioecious. However, the male structures (antheridia) mature up to a month before the female structures (oogonia) and then disintegrate which means that the absence of one type of sexual structure cannot reliably be used as evidence of dioecy. Fortunately, there is also a size difference of the sexual structures of the two species (the oospore is the dark-coloured spore within the oogonia): N. flexilis Agardh: M onoecious; antheridia 500-625 µm; mature oospore 500-575 µm. N. opaca Agardh: Dioecious; antheridia 650-775 µm; mature oospore 375-425 µm. Although there are reputed to be vegetative differences between the two species, there is considerable overlap and none of these are reliable. Sterile material should therefore continue to be recorded as N. flexilis aggregate. Some of the forms of the two species may deserve recognition after more study; for example, a very slender form of N. opaca, similar in stature to N. gracilis, has been recorded from several montane lakes in Scotland and Wales. N. opaca is by far the most frequent of the two species. While N. flexilis seems to be quite widely distributed it is mostly rare but becomes more frequent towards the south-east. While N. opaca occurs in a wide range of situations, N. flexilis seems to be restricted to more mesotrophic to eutrophic waters.

References Groves, J. & Bullock, G. R. (1920). The British Charophyta. Volume 1. Nitelleae. Ray Society, London. M oore, J. A. (1986). Charophytes of Great Britain and Ireland. BSBI Handbook No. 5. BSBI, London. Stewart, N. F. & Church, J. M . (1992). Red Data Books of Britain and Ireland: Stoneworts. JNCC, Peterborough. Wood, R. D. & Imahori, K. (1965). A revision of the Characeae. J. Cramer, Weinheim. Author

N. F. Stewart, January 1998.

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Nitella opaca (from Groves & Bullock 1920). (a) male plant, (b) female plant, (c-f) apices of dactyls, (g) apex of dactyl of var. attenuata, (h) branchlet node with antheridium (i) branchlet node with oogonia, (j) mature oogonium after shedding coronula (k) oopsore.

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Plant Crib NUPHAR N. lutea and N. pumila may show considerable local variability but form reasonably homogeneous units throughout Europe. Their hybrid, N. × spenneriana (N. × intermedia), is also relatively uniform and often occurs in the absence of both parents. Introgression is rare (Heslop-Harrison 1953). The following Table and diagrams have been abstracted from Heslop-Harrison (1953). M easurements refer to FRESH specimens as material usually shrinks considerably (10-20%) when dried. Leaf characters are given, but it is probably best to confirm identification based on these using floral characters. N. × spenneriana usually has a low fertility, the fruits ripen normally but c. 80% of the seeds abort. Please note figures in Table are means: It is not stated whether the error ranges given in Heslop-Harrison (1953) are standard errors or standard deviations N. lutea (L.) Sm.

N. × spenneriana Gaudin

N. pumila (Timm) DC.

Largest sepal

34 × 32 mm (Fig. a)

25 × 20 mm (Fig. b)

20 × 13 mm (Fig. c)

Largest petal

15 mm long (Fig. d)

8 mm long (Fig. e)

5 mm long (Fig. f)

Stigmatic disc

Variable; 12.4 mm across, rays linear to elliptic, margin entire (rarely sinuate) (Fig. g)

9.2 mm across, rays narrowly elliptic, margin distinctly undulate (Fig. h)

8 mm across, rays linear, margins uniformly deeply scalloped (Fig. i)

No. carpels/ (12-)13-20(-21) stigma rays

9-13(-14)

8-11

Leaves max. length × width

30 × 26 cm

15 × 11 cm

13 × 10 cm

Leaves

23-28 lateral veins

15-22 lateral veins

11-18 lateral veins

Petiole cross section

± Triangular

Narrowly triangular

Elliptic or lens-shaped, but may have slight angles

Vascular bundles

17-23

8-13

7-12

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Sepal shapes of (a) N. lutea, (b) N. × spenneriana, (c) N. pumila.

Reference

Heslop-Harrison, Y. (1953). Watsonia 3: 7-25.

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Plant Crib

OPHIOGLOSSUM AZORICUM, O. VULGATUM AND O. LUSITANICUM O. vulgatum is a variable plant in leaf size and texture and small plants of grazed sand dune slacks have been recorded in error as O. azoricum. The latter species may have arisen as a hybrid of O. vulgatum with O. lusitanicum and shares some characters of that species. The latter, although very rare in Britain, is therefore included in the table below. The morphology and distribution of O. azoricum was discussed by Paul (1987).

Ophioglossum vulgatum L.

O. azoricum C. Presl

O. lusitanicum L.

Plant

8-30 cm tall, typically with leaves appearing singly in late May to mid June, dying down mid August / September

3-8 cm tall, leaves typically clustered in pairs or triplets, appearing in May, dying down in July

1-1.5 cm tall, typically with leaves clustered in pairs, appearing in early winter (October) and dying down late April

Leaf-blade

Up to 150 mm long, held erect, broadly ovatelanceolate to ovate, widest below the middle, apex often broadly rounded, or obtuse, base attenuate to cordate and often clasping the leaf stalk (Fig. a)

9-22(-40) × 4-10(-14) mm, convex, reflexed, broadly elliptic-lanceolate to ovate, widest at or just below the middle, apex acute, base cuneate (Fig. b)

8-23(-38) cm long, typically reflexed and lying close to turf but may be more erect, narrowly lanceolate, widest at the middle, narrowing to the base and acute apex (Fig. c)

Leaf-blade texture

Herbaceous, if thick then soft

Often fleshy, ± thick

Thick, very fleshy, often glossy

Herbaceous, sporangia 413(-17) pairs

Stout and fleshy, sporangia 3-8 (-13) pairs

Stalk bearing Herbaceous, sporangia 10fused sporangia 44 pairs (sporophore)

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Habitat and leaf-shapes in Ophioglossum: (a) O. vulgatum, (b) O. azoricum, (c) O. lusitanicum.

Reference

Paul, A .M. (1987). Fern Gazette 13:173-187.

Authors

A. C. Jermy & J. M. Camus (Fern Guide 1991).

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PAPAVER

1. Papaver, key to non-flowering plants P. somniferum 2

1 1

Plant glabrous; leaves lobed but not deeply divided, glaucous and waxy Plant hairy

2

Coty ledons long and narrow, more than 8 times as long as wide (Fig. a); leav es pinnatisect, leaf -segments straight-sided, tapering to a bristle-tipped point, normally dark-green

2

Coty ledons between three and eight times as long as wide (Figs. b, c); leav es v ery v ariable, pinnatisect to pinnate, segments curv ed-sided, grey -green 3

3

Stem with patent hairs, sometimes also with appressed hairs; leav es f requently with a large terminal segment (Fig. b)

3

Stem with closely appressed hairs only

4 4

Latex white to cream (tear leaf or stem) P. dubium subsp. dubium Latex y ellow (can be white f or a f ew records); a generally bulkier plant, but other v egetativ e characteristics are not suff iciently dependable to distinguish this from subsp. dubium (see also below)P. dubium subsp. lecoqii

P. argemone & P. hybridum (these species cannot be distinguished before flowering)

P. rhoeas 4

Cotyledons

Leaf shapes. (a) P. argemone, (b) P. rhoeas, (c) P. dubium (del. M. Reed).

Habitats and status of Papaver species P. argemone L. Almost exclusively in arable land on both chalk and sands, but occasionally in quarries and other disturbed sites. Uncommon, most frequent in the east and south-east, but still as far north as the Firth of Forth (Scarce Plants).

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Plant Crib P. hybridum L. Almost exclusively in arable land on chalk. Very rarely in other disturbed sites and on other calcareous soils. Rare, but still quite frequent in central S England (Scarce Plants). P. somniferum L. A relic of former cultivation. An occasional weed in arable land especially in SE England. Also a garden escape. P. rhoeas L. M ainly in arable land, but also in other disturbed sites and on waste ground. Still widespread and locally common, especially on chalk and sands and where crop rotations have recently included oil-seed rape. Seeds are thought to have a very long persistence in the soil. P. dubium L. subsp. dubium. Almost exclusively in arable land but occasionally in other disturbed sites. Widespread throughout Britain, more common further north than P. rhoeas. P. dubium subsp. lecoqii (Lamotte) Syme. In arable land, but also common in other disturbed places (see below). Distribution incompletely known as a result of similarity to subsp. dubium. Author

P. J. Wilson, December 1997.

2. Papaver dubium subspecies The two subspecies of Papaver dubium L. are very similar morphologically, but differ consistently in some characters. They also appear to be ecologically well separated. The following notes based on studies in the Home Counties may help in their recognition. Subsp. dubium is the classic smooth long-headed poppy, most often of disturbed and waste ground. It is a plant of somewhat acidic to neutral, freely draining, often gravelly ground. It is not so often encountered as an arable weed, being more a plant of roadsides, building sites, etc., although this may have more to do with the distribution of land uses on its characteristic soils. It will also turn up in atypical habitats where soil is dumped. Subsp. lecoqii has been found to be very clearly associated with highly calcareous soils, usually somewhat clayey, such as chalky boulder clay, or the damper ground on chalk itself (e.g. on Chalk M arl). It is almost never found on acidic soils, and is not especially associated with gravels. It is also a roadside plant, but, contrary to published literature, is quite often found as an arable weed and is widespread and quite common on the appropriate soil types in SE England, at least. It is also often the first of the poppies to flower, some two or three weeks earlier than subsp. dubium or P. rhoeas. The most effective way of distinguishing the two plants is to test a stem for its sap colour. In subsp. lecoqii this is always bright yellow immediately or after a few seconds on exposure to air, unless the plant has dried up. This applies equally to young plants and those long-gone to seed, and so they can be distinguished safely in the field without the flowers. The following comparative Table gives other pointers to the two subspecies, in descending order of usefulness. Other published differences, such as shape of the capsule and seed colour do not seem to be as useful. Both plants are upright and wiry in growth habit, and young foliage without stems (and therefore accessible sap) is all but indistinguishable, except by suggestion from habitat. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

Papaver dubium flowers viewed from above (a) subsp. lecoqii, (b) subsp. dubium.

Subsp. lecoqii (Lamotte) Syme

Subsp. dub ium

Latex

Yellow or turning yellow when fresh, red when dry

White, creamy or milky/watery when fresh, brown to black when dry

Petals

Almost always clearly separated from each other towards the base (but may slightly overlap towards the apex) (Fig. a)

Rounder than in lecoqii, therefore overlapping towards the base, and separating only towards the apex (Fig. b)

Flower colour

Usually a clear, pale, almost orange-red, distinctly different from P. rhoeas, and never with black basal blotches

Usually a pale red, but quite often more like P. rhoeas, but again never with black blotches at the base of the petals

Stamens

Usually a pale brownish or yellowish colour, at least when fresh

Often a dark purplish-black colour, but sometimes dark brown

Leaves

Often fairly broad, but very deeply dissected, the ultimate segments tapering to fine, sharp points

Often quite narrow, also deeply dissected, but with the ultimate segments usually more or less parallel-sided until somewhat abruptly acute apex

Foliage colour

Often a glaucous or bluish green

Sometimes greyish, but more usually a pale green

Reference

Kadereit, J. W. (1988). Notes Royal Botanic Garden Edinburgh 45: 225-286.

Author

T. J. James, December 1997. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

PARIETARIA JUDAICA / P. OFFICINALIS The larger-leaved, more erect, alien P. officinalis is occasionally recorded in Britain (cf. Wurzell 1993) but is easily overlooked with the smaller, more decumbent native P. judaica (NB these names have historically been much confused). They can be distinguished as follows (Townsend 1968) (see also figures overleaf): P. officinalis L.

P. judaica L.

Female flower

2.7-3 mm in fruit, much exceeding the bracts, conspicuous; perianth segments broadly lanceolate

2-2.3 mm in fruit, just exceeding bracts, inconspicuous; perianth segments narrowly lanceolate, subaristate

Hermaphrodite flower

Perianth remaining campanulate in fruit, not exceeding 3 mm

Perianth tubular in fruit, growing larger to 3-3.5 mm

Achene

1.5-1.8 mm long, frequently distinctly asymmetrical

1.0-1.2 mm long

Hermaphrodite

Female

Female opened

Hermaphrodite

Parietaria officinalis

Reference

Female

Female opened

Parietaria judaica

Townsend, C. C. (1968). Watsonia 6: 365-370. Wurzell, B. (1993). BSBI News 63: 27.

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POLYGALA 1. Polygala vulgaris (P. oxyptera) The revision of Polygala by Heubl (1984) has shown that P. vulgaris subsp. oxyptera is a central European - sub-M editerranean taxon which does not occur in the British Isles. It seems that plants previously referred to P. oxyptera auct. in Britain are best referred to P. vulgaris subsp. collina, and detailed records are required to assess their distribution (specimens of subsp. collina were cited from V.c. 1, 13, 17, 41 & 57 by Heubl).

Fig. a. Anastomising veins (arrowed)

The appropriate part of Heubl’s key is abstracted as below. Anastomising veins are the little veins which join the bigger veins together (Fig. a). Note that Stace’s New Flora has confused the number of anastomising veins in subsp. vulgaris with the number of lobules on the corolla in subsp. collina. P. vulgaris subsp. vulgaris: Flowers blue or purplish; plants ± erect, robust, many stemmed; upper stem leaves conspicuously larger than lower leaves, 25-40 mm long, basal leaves elliptical; wings 6-8.5 × 3.5-5 mm, abruptly contracted at the base with a short tail, approximately as wide as the capsule, with 6-20 anastomising veins; lobules on the corolla 14-32; style as long as the ovary. P. vulgaris subsp. collina (Rchb.) Borbás: Flowers white; plants ± ascending to ascending-erect, more slender with few stems; upper stem leaves little larger than lower leaves, 10-30 mm long; wings 4-6 × 2-3.5 mm, gradually tapering toward the base, a little narrower and as long as or longer than ripe capsule, with 4-8 anastomising veins; lobules on the corolla 8-16(-22); style longer than ovary. Reference

Heubl, G. R. (1984). Mitt. Bot. Muenchen 20: 205-428.

Author

J. Kirschner, February 1998.

2. Polygala serpyllifolia / P. vulgaris Good, healthy material of P. serpyllifolia and P. vulgaris can be separated by at least some of the lower leaves (and occasionally the upper leaves too) being opposite to sub-opposite in the former, and all leaves alternate in the latter. P. serpyllifolia is also generally smaller, with smaller, blue to slaty-blue flowers, whilst P. vulgaris is more robust with larger flowers which are more variable in colour (blue, white or pink). P. vulgaris appears to have been widely over-recorded. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib In many cases it is not so clear and further examination may be required. The lower leaves, which are shorter and broader than the upper leaves, are often very crowded and it is then difficult to tell if they are opposite or not. If some of these lower leaves have dropped off, the relative positions of the nodes must be examined with a lens. The following Table has been compiled from CTM and Flora Europaea. P. serpyllifolia J. A. C. Hose

P. vulgaris L.

Lower leaves

At least some opposite or subopposite

All alternate

Racemes

3-10 flowered

10-40 flowered

Sepals

Outer 1.5-2.5 mm, inner (=wings) 4.5-5.5 mm long

Outer c. 3 mm, inner (=wings) (3)4-7(-8) mm long

Capsules

Shorter and wider than wings

About as long and narrower or as wide as wings

Seeds

Ovoid (excluding appendage)

Oblong-ellipsoid (excluding appendage)

3. Polygala calcarea / P. vulgaris In chalk or limestone grassland these two species are regularly confused, especially later in the season when rosettes have disappeared. As a rule until June, if you are uncertain if it has a basal rosette or not, then it is probably not P. calcarea. The species look different, yet it is often difficult to put the differences into words; often the distinctive differences in flower colour can allow the taxa to be readily named from a distance once your eye is in. Basal rosette/lower stem leaves are obovate and obtuse in both species despite what the floras say; the differences between the stem leaves are better but require careful comparison. The main problems result from assessing the variation in the three types of leaves on the plant. Basal rosette leaves, if present, form an obvious basal rosette which persists until mid-summer, the leaves yellowing just before they drop. The leaves are typically obovate and have a short, broad, poorly differentiated petiole. Lower stem leaves tend to be similar in shape to the basal leaves but much smaller (1/4-1/3 as long). The upper stem leaves tend to be sessile, narrow and more pointed but are larger than the lower stem leaves. In addition, sterile shoots can be put out from mid summer onwards with leaves rather like rosette leaves; these are best ignored. Another field character is the prominent stamens/lobules Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib of P. calcarea which protrude like an African comb (Fig. c). The stamens of P. vulgaris and P. serpyllifolia are ± contained in the flower (Fig. d). There is a recent map of P. calcarea in Scarce Plants (under-recorded in E Sussex). A hybrid between the two has also been recorded; it is sterile and intermediate.

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Plant Crib Polygala calcarea F. W. Schultz

P. vulgaris L.

Basal rosette

Conspicuous until mid summer; leaves obovate, obtuse

Absent (small obovate leaves may cluster along the base of the stem)

Upper stem leaves

Oblanceolate to ellipticoblanceolate, obtuse (Fig. a)

Linear-lanceolate to ± ellipticallanceolate, more acute (Fig. b)

Inflorescence

Erect, short, flowers crowded at apex

Erect to ascending, longer with flowers more spaced

Flowers

Usually deep blue, sometimes whitish, exceptionally pink

Variably white, pink or light blue

Inner sepals (note 1)

(3-)4.5-6.0(-6.5) mm long

Subsp. vulgaris 6-8.5 mm long, subsp. collina 4-6 mm long

Stamens/lobul Exerted (Fig. c) es

Contained in flower (Fig. d)

Note 1.

M easure on fully open flowers.

Upper stem leaves (top) and basal stem leaves/rosette leaves (bottom). (a) P. calcarea, (b) P. vulgaris

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Plant Crib

Flowers with stamens/lobules (c ) P. calcarea, (d) P. vulgaris.

Authors

R. FitzGerald, D. A. Pearman & T. C. G. Rich, February 1998.

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Plant Crib POLYPODIUM Three species of Polypodium occur throughout the British Isles. Two (P. interjectum and P. vulgare) are widespread and frequently hybridise to form P. × mantoniae Rothm.; it is the most frequent hybrid and often once established, forms large clones. The third species (P. cambricum) shows a South Atlantic/Mediterranean distribution preferring limestone rocks in areas where the January mean temperatures are above 2o C. It also hybridises with the other two when growing close by, forming with P. interjectum, P. × shivasiae Rothm. and with P. vulgare, P. × font-queri Rothm. The leaf-shape of the hybrids is intermediate between the parents and indurated cell numbers often vary to cover the whole range seen in the parents. Hybrid spores in Polypodium are colourless contrasting with the yellow-gold colour of viable spores and frequently sporangia do not dehisce. Polypodium cambricum L.

P. interjectum Shivas

P. vulgare L.

Leaves

5-50 cm long, yellowgreen, new leaves produced autumn/winter; turning yellow and dying down in late spring or early summer

15-60 cm long, midgreen, new leaves produced late summer and autumn; wintergreen

5-25 cm long, midgreen, new leaves produced early summer; wintergreen

Leaf-blade

Broadly ovate-deltoid often with a long, narrow apical segment, pinnatisect

Narrowly ovate to oval, pinnatisect

Narrowly lanceolate to linear (but juvenile leaves triangular), pinnatisect to an obvious herringbone pattern

Leaf segments

Up to 7 cm long, usually serrated and with acute apices, lowest pair inflexed

c. 5 cm long, usually slightly serrate, tips tapering or bluntly rounded, lowest pairs somewhat inflexed

c. 2-4 cm long, entire or barely serrate, tips rounded, lowest pairs not inflexed

Rhizome scales

Narrowly triangular with a long wispy apex

Narrowly triangular with long, but not wispy, apex

Narrowly triangular with acute, but not long and twisted

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Plant Crib Sori

Oval, on upper 1/3 of leaf, paraphyses present

Initially oval, on upper 1/3 - 2/3 of leaf, paraphyses lacking

Round, on upper 1/4 - 3/4 leaf, paraphyses lacking

Sporangium

Annulus dark brown; indurated cells (4-) 510, 21-26 × 81-100 µm; basal cells 3-4

Annulus pale brown; indurated cells (4-) 7-9 (-13), 28-35 µm × 76-86 µm; basal cells 2-3

Annulus red-brown; indurated cells (7-) 10-14 (-17), 22 -28 × 60-80 µm; basal cell 1

Spores maturing

In early spring

Summer to autumn

In summer

Notes 1. The best time to use this diagnostic character is early in the sporangia ripening sequence (which varies between species) and when the sporangia are yellow. With a ×10 lens the contrasting colour can be easily seen. The number of indurated cells and basal cells are best seen under a binocular at ×40 or above. 2. Illustrations of sporangia del. R. H. Roberts, with permission of C. A. Stace and Cambridge University Press. Authors

A.C.Jermy & J.M.Camus (Field Guide, 1991.)

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Plant Crib POLYSTICHUM Polystichum aculeatum, P. lonchitis (L.) Roth and P. setiferum show differences in ecological requirements: P. aculeatum and P. lonchitis preferring rocks and soils with relatively high calcium content and P. setiferum on soils which are base-poor. All three species hybridise but hybrids with P. lonchitis are very rare.

1. Hybrids with Polystichum lonchitis P. aculeatum and P. lonchitis do grow together on upland calcareous rock scree and the hybrid P. × illyricum should be searched for. It has been recorded for V.c. 105, 108 & H29. The other hybrid, P. setiferum × lonchitis (P. × lonchitiforme) is rarer (recorded only from V.c. H29) but both are likely to occur where the two parents grow together. Both hybrids have abortive sporangia and spores. The lowermost pinnae show the best diagnostic characters (see Figures below).

Lowermost pinnae of Polystichum hybrids: (a) P. lonchitis L. (b) P. × illyricum (Borbás) Hahne; (c) P. × lonchitiforme (Halácsy) Bech.

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Plant Crib 2. Polystichum aculeatum / P. setiferum / P. × bicknellii These two species can grow close together in areas of mixed geology, and there may form the hybrid P. × bicknellii; which is intermediate in morphology and frequently shows hybrid vigour. It is probably more common than hitherto recorded. Polystichum aculeatum (L.) P. × bicknellii (H. Christ) Roth Hahne

P. setiferum (Forssk.) T. Moore ex Woyn.

Leaves

30-90 cm; leaf-blade narrowly lanceolate, variable in division, 1-pinnate-pinnatisect to 2-pinnate, tapering to base, glossy, deep green, feels stiff; petiole usually less than 1/6 leaf length

Up to 1.5 m; leaf-blade lanceolate, 2-pinnate, glossy, deep green, younger leaves bright green, feels stiff; petiole usually more than 1/6 leaf length

Up to 1.5 m; leaf-blade lanceolate, 2-pinnate, truncate at base, mildly glossy, bright green, feels soft; petiole usually more than 1/6 leaf length

Pinnae

Not overlapping, lowest pinna c. 1/2 length of middle pinnae

Not overlapping, lowest pinna c. 1/2 length of middle pinnae

Well-spaced apart, lowest pinna ± equal in length to middle pinnae

Pinnules

Those nearest rachis usually sessile and decurrent from an acute angled base and tapering to very acute angle at apex

At least some nearest rachis stalked into an obtuse (90°) angled base and tapering to obtuse hair-tipped apex

Those nearest rachis stalked into an obtuse angled base, tapering to obtuse hair-tipped apex

Spores

(30-) 39–42 (-45) µm long, dark brown

Mostly all abortive (shrivelled), dark

c. (30-) 33–36 (38) µm long, yellow

There is a growth form of P. aculeatum scattered throughout its range (var. cambricum (Gray) Hyde & A. E. Wade, reduced to form in Hutchinson & Thomas 1996) which has been confused with P. lonchitis. It can be distinguished by noting two distinct lobes at the base of the lower pinnae. These are absent in the usually more coriaceous P. lonchitis (see Figure above and Table above). References Hutchinson, G. & Thomas, B. A. (1996). Welsh ferns. National M useums and Galleries, Cardiff. Authors

A. C. Jermy & J. M. Camus (Field Guide 1991); revised A. C. Jermy, January 1998.

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Plant Crib

POTAMOGETON AND RUPPIA The BSBI Handbook Pondweeds of Great Britain and Ireland by C. D. Preston (1996) is the essential reference work to these two genera. Two updates are included here, with reminders about collecting and examining stipules. A key to taxa with opaque leaves is also included as useful supplementary information. Recent maps are given in both the Pondweed Handbook and in Aquatic Plants. Collecting material If possible collect a whole stem from the base. Flowers or fruits are usually not essential in Potamogeton, but collect a few additional separate ones to supplement the specimen if they are available. For broadleaved species try to collect main-stem leaves as well as branch leaves. For narrow-leaved species, ensure that the material includes enough young shoots to permit dissection of young stipules. Shape of stem in cross-section and of leaf apex should be noted before pressing, as well as characters of stipules including whether open or closed and presence or absence of keels. Narrow-leaved species, along with all other delicate aquatics, are best floated out before pressing. The specimen is arranged under water on a sheet of paper in a tray (plastic photograph trays are ideal); the sheet is slowly lifted out from one end, minor rearrangements being made with forceps if the specimen is disturbed by the flowing water. Fine nylon curtain mesh is even easier to use as the water drains through the mesh and leaves the specimen undisturbed. The paper or mesh is then placed in a flimsy and dried in the usual way, but remember that aquatics dry rapidly and overheating can make the specimens very brittle. Examination of stipules In identifying linear-leaved Potamogeton species it is essential to establish the structure of the stipules; failure to do this is a common cause of misidentification. Stipules can only be seen with ease under a binocular microscope. Fresh material is the easiest to work with, but portions of pressed specimens can also be examined if they are first soaked in water for 10-15 minutes. To examine the stipules, detach the end of a stem which bears several young leaves. Place this in a few drops of water on a microscope slide. The stipules are translucent and clasp the stem above the point of insertion of the leaves. With a sharp razor cut the stem immediately above the point where the leaf joins. The lower stem, with the attached leaf, can be then discarded. Hold the upper stem and gently pull the stipule over the cut end of the upper stem using a fine pair of forceps. To examine a second stipule, repeat the process on the next leaf towards the stem apex. The stipules of some species are tubular and form an unbroken cylinder. Often the easiest way to see this is to turn the lower end of the stipule up towards the microscope, so that you look straight down on the cut end. Another method is to cut a thin section of the stipule at its lower end and examine face-down on the microscope slide. The stipules of other species do not form a closed tube, but the free ends overlap; they are therefore said to be open and convolute. A simple way to remember that

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Plant Crib P. berchtoldii and P. trichoides have open stipules is that the names berchtoldii and trichoides contain the letter ‘e’ which is rolled like an open stipule. Tubular stipules tend to split from the top as they age, hence the need to choose young stipules towards the stem apex and to examine the lower end of the stipule. Once a little practice has been gained, the stipular morphology can be established on almost all specimens. Decaying plants collected in autumn once active growth has ceased are the most troublesome.

a

b

Cross section of sheaths (a) stipule closed (tubular), (b) stipule open (convolute).

1. Potamogeton × gessnacensis (P. natans × P. polygonifolius) P. × gessnacensis has been recorded in V.c. 49, 106 & 112, and could well occur elsewhere. The hybrids are variously intermediate between the parents and are highly sterile. The inflorescences of the hybrid are narrow (as the stamens protrude through closed perianth segments) and relatively short (Preston et al. 1988). Suspected hybrids should be collected for confirmation. P. natans L.

P. × gessnacensis G. Fisch.

P. polgonifolius Pourr.

40-170 mm long, green or buff, opaque

20-88 mm long, brown, buff, green or greenish brown, opaque to translucent

10-50 mm long, brown, translucent

Longitudinal Translucent veins of fresh floating leaves

Opaque or translucent (if translucent usually very narrow)

Opaque

Discoloured junction between petiole and lamina

Absent or trace visible

Absent

Inflorescence 20-60 mm long

8-28 mm long

10-42 mm long

Fertility

Sterile

Fertile

Stipules

Usually present, rarely absent

Fertile

Reference

Preston, C. D., Bailey, J. P. & Hollingsworth, P. M . (1998). Watsonia 22: 61-68.

Author

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Plant Crib 2. Potamogeton × bottnicus (P. pectinatus × P. vaginatus) A hybrid Potamogeton in the Rivers Till and Tweed (V.c. 68 & 81) is apparently referable to P. × bottnicus, a cross between P. pectinatus and the Scandinavian P. vaginatus Turcz. (Preston et al. 1998). Characters distinguishing P. vaginatus are given in the Pondweed Handbook on page 133, and the hybrid can be keyed out as follows (this key can replace leads 2-4 in the key to Group F on the same page, and is numbered following the Pondweed Handbook): 3 4

2a All sheaths open to the base 2b Some or all sheaths tubular at the base

3a Mature leav es on the v egetativ e stems usually acute to f inely acuminate at the apex; stigmas borne on a distinct style c. 0.2 mm long; pollen well f ormed; f ruits 3.3-4.7 mm 21 P. pectinatus L. 3b Mature leav es on the v egetativ e stems more or less truncate, rounded or obtuse at the apex; stigmas sessile; pollen misshapen; fruits not developing P. × bottnicus Hagstr. 4a Stems branched at base, otherwise unbranched or v ery sparingly branched; all sheaths tubular at the base; stigmas sessile; pollen well-f ormed; fruits 2.2-2.8(-3.2) mm 20 P. filiformis Pers. 4b Stems usually sparingly or richly branched abov e the base; all sheaths tubular at the base or some tubular and others open and conv olute; stigmas sessile or borne on a distinct sty le; pollen misshapen; fruits not developing47 P. × suecicus K.

Richt.

Reference

Preston, C. D., Hollingsworth, P. M . & Gornall, R. J. (1998). Watsonia 22: 69-82.

Author

C. D. Preston, December 1997.

3. Taxa with opaque leaves The ± opaque, ± floating leaves of pondweeds are not usually used for identification. Yet there are occasions when these are the only leaves available, and certain features can be used to make a positive identification. However, this will not be possible on every occasion particularly with small fragments, and a combination of characters should be considered before making a decision. M ost confusion will be with P. polygonifolius which overlaps in many of its characters with the other species considered here. P. coloratus never has fully opaque leaves, but occasionally they can be nearly so, and hence is also given in the key. The key should be used with caution on leaves which have developed in exposed dried-up situations. Three other British species can have opaque floating leaves, but these always have translucent underwater leaves as well, except the rare P. nodosus which has translucent leaves which may rot away completely. This species has long (up to 20 cm) lanceolate leaves with cuneate bases, and long stipules (5-9 cm). In P. alpinus the floating leaves are not usually fully opaque, and are often nearly translucent at their bases. Floating leaves of P. epihydrus are indistinguishable from P. polygonifolius, though in transitional leaves the petioles are flattened and have a thin band of translucent tissue along their length. Several hybrids with opaque leaves occur, but these are uncommon, and they cannot be differentiated from the true species on the characters of the opaque leaves alone.

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Plant Crib 1

1

2

2

3

Petiole widening towards the apex (normally at least twice the width of the base of the petiole), usually less than half the length of the blade, but sometimes equalling the leaf blade in deeper water; some leaf blades, at least in the upper summer leav es, rounded or truncate at base, and decurrent onto the petiole f or up to 1.5 cm, with some main lateral v eins separating f rom the midrib in the decurrent part of the leaf ; leav es with rounded / truncate bases of ten broadest markedly below the middle; midrib narrowing as the major lateral v eins branch of f f rom it, becoming only slightly stronger than the major laterals through the remaining part of the leaf P. coloratus Hornem. Petiole of constant width, or only slightly widening near the apex (less than twice the width of the base), only less than half the length of the leaf blade in some of the y oungest unopened leav es; base of leaf blade rounded or truncate and decurrent on the petiole f or less than 0.5 cm, or cuneate; major lateral v eins not separating f rom the midrib in the decurrent part of the blade; leav es broadest near the middle; midrib narrowing gradually throughout the length of the leaf 2 Flexible joint (section of paler tissue up to 2.5 cm long) of ten present at the apex of the petiole; veins of aquatic leaves more translucent than the blade, cross-v eins obscure (see note 1); leaf v eins (6-)9-14(-16); stipules long (4-17 cm), closely v eined (c. 4 v eins per mm when fresh), keeled P. natans L. Flexible joint at the apex of the petiole nev er present; v eins of leav es less translucent than the blade, and cross-v eins distinct (see note 1), leaf v eins (5-)6-8(-12); stipule short or intermediate (less than 5 cm), closely or sparsely v eined, usually with two more prominent strengthening v eins and sometimes ± keeled 3 Stipule short (less than 2.5 cm), closely v eined (c. 4 v eins per mm when f resh), the upper sometimes ± keeled; translucent leav es absent only in terrestrial plants (reduced to short bladeless phy llodes); opaque leav es cuneate at base P.

gramineus L. 3

Stipule intermediate (1-5 cm), sparsely v eined (c. 2 v eins per mm when f resh), with two more prominent strengthening v eins, but not keeled; translucent leav es f requently absent in aquatic plants and nev er reduced to bladeless phy llodes; opaque leav es cuneate, rounded or truncate at base

P. polygonifolius Pourr. Notes to Potamogeton Table on next page 1. The leaf vein characters are best viewed by holding the leaves up to the light. Only leaves of aquatic plants should be used; in terrestrial plants the leaf veins of P. natans become more opaque, but these plants should be identifiable by the presence of long phyllodes. 2. Adjacent to the midrib the cross veins ascend at an angle but become more transverse towards the leaf edge. 3. The differentiation of a decurrent wing from the main part of the leaf blade is only possible when the blade is rounded or truncate at base. This character is therefore not applicable to P. gramineus which always has cuneate leaf bases. Author

N. F. Stewart, February 1988, minor updates January 1998.

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Plant Crib Potamogeton natans

P. polygonifolius

P. coloratus

P. gramineus

Lateral v eins

(6-)9-14(-16) pairs

(5-)6-8(-12) pairs

4-10 pairs

5-10 pairs

Veins of f loating leav es (note 1)

Lighter than rest of leaf

Darker than rest of leaf

Darker than rest of leaf

Darker than rest of leaf

Cross v eins of f loating leav es

Obscure

Visible

Visible

Visible

Extent of ascending cross-v eins (note 2)

c. 0.25 of leaf width

c. 0.75 of leaf width

c. 0.25 of leaf width

c. 0.75 of leaf width

Where broadest

± Middle

± Middle

Often broadest markedly below the middle

± Middle

Leaf base

Rounded / cuneate / truncate

Rounded / cuneate / truncate

Rounded / cuneate / truncate

Cuneate

Opaque leaves

Petioles of opaque leaves Widening near apex

Not widening

Slightly less than 2 × width at base

More than 2 × width at base

Not widening

Distinctly winged (note 3)

Sometimes a few mm

Sometimes a few mm

Up to 1.5 cm

Not applicable

Length v s. leaf blade length

> 1 times as long as blade

>0.5 times as long as blade (rarely <0.5 in 1-2 unopened leaves)

0.1-0.5 times as long as blade (rarely >0.5 in deep water)

0.5-5 times as long as blade

Flexible node

± P resent at apex

Absent

Absent

Absent

Length

4-7 cm

1-5 cm

2-5 cm

0.5-2.5 cm

Apex

Acute / subacute

Obtuse, often hooded

Obtuse and hooded

Obtuse to subacute; often rolled and appearing acute

Vein spacing when f resh

c. 4 per mm

c. 2 per mm

c. 2 per mm

c. 4 per mm

Keeled

Yes

No

No

Yes / no

Phy llodes

Longer than true leaves + petiole

Absent

Absent

P resent on terrestrial plants, and sometimes on aquatic plants, to as long as true leaves + petiole

Stipules

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Plant Crib

POTENTILLA 1. Potentilla crantzii / P. neumanniana When grazed (e.g. on shingle), P. crantzii may be procumbent and be mistaken for P. neumanniana (P. tabernaemontani Asch.) if other characters are not examined (Edelsten 1996). A few populations are intermediate between the two species and may have arisen by hybridisation (Smith 1971). The stipule character can be used for herbarium material as the other characters are difficult to assess on pressed material. The terminal teeth on the leaflets seem to vary more than as described in the Table below. P. neumanniana is generally a plant of lowland chalk and limestone, sometimes much more abundant after drought years. P. crantzii occurs on basic rocks and crags mainly in the uplands, but does occur washed down on shingle. M aps of both species are given in the Scarce Plants. P. neumanniana Rchb.

P. crantzii (Crantz) Beck ex Fritsch

Shoots

Prostrate, usually rooting and forming mats

Ascending, forming clumps, not forming mats except when grazed

Free part of stipule on stem leaf

Linear-lanceolate, c. 4.2-7.6 times as long as wide; apex acute (Fig. a)

Ovate, c. 1.9-3.5 times as long as wide; apex obtuse (Fig. b)

Terminal tooth Usually markedly smaller than its of basal leaflet neighbours, relative width 0.60.8(-0.95)

Scarcely smaller than its neighbours, relative width 0.750.9

Flowers

15-25 mm diameter, often with orange spot at base of petal

10-15 mm diameter, usually without orange spot

Stipules of stem leaflet (a) Potentilla neumanniana, (b) P. crantzii.

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Plant Crib References Edelsten, J. (1996). BSBI Scottish Newsletter 18: 15-16. Smith, G. L. (1971). New Phytologist 70: 607-618.

2. Potentilla erecta Richards (1973) described the occurrence of P. erecta (L.) Raeusch. subsp. strictissima (Zimmeter) A. J. Richards, a robust upland race with sparse flowers, in Britain and Ireland. It occurs in dwarf-shrub heath, on rocks and ledges, and less commonly in grassland, on peat or mineral soils at a range of altitudes (not just upland). It has been recorded from V.c. 3-5, 42, 46, 48, 64, 66, 70, 81, 90, 95, 96, 98, 99, 106, H3, H12, H14, H20, H21, H23, H25-29, H36-40 (Richards 1973, Rich & Scannell 1990). It is not uncommon and should be looked for elsewhere. Intermediates with the widespread subsp. erecta have been found in one locality where the two subspecies occur together, but the taxa are usually readily separated elsewhere. Subsp. erecta

Subsp. strictissima

Habit

Weak, often decumbent, usually 516(-20) cm in length

Erect, usually 10-40 cm in length

Stem leaves

Uppermost usually 5-14(-20) mm long; weakly toothed (teeth usually less than 1.5 mm long) to only ½ way to base

Uppermost usually (12-)16-28 mm long; coarsely and acutely serrate (teeth usually exceeding 1.5 mm long) to base

Stipules

Less than 10 mm long, divided to ½ way

Longer than 10 mm, divided ± to base

Petals

Usually 2.5-4.5(-5.0) mm long

Usually (3.8-)4.5-6.5 mm long

References Richards, A. J. (1973). Watsonia 9: 301-317. Rich, T. C. G. & Scannell, M . J. P. (1990). Irish Naturalists’ Journal 23: 224-225.

3. Potentilla erecta / P. reptans / P. anglica and hybrids P. erecta (L.) Raeusch. and P. reptans L. are well known and easily recognised but P. anglica and its hybrids, P. × mixta Nolte ex Rchb. (P. anglica × P. reptans) and P. × suberecta Zimmeter (P. anglica × P. erecta), are extremely difficult to distinguish from one another. The hybrids are common and P. × mixta, which is seed-sterile but spreads very effectively by runners, is more common in most localities than P. anglica Laich itself. It is often found in isolation from the parents whilst P. × suberecta only occurs within the vicinity of P. erecta and P. anglica.

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Plant Crib

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Plant Crib The following Table summarises the main distinguishing features between P. anglica and the hybrids. All characters should be considered together when making a diagnosis. Potentilla × mixta

P. anglica

P. × sub erecta

Habit

Prostrate, rarely branching

Procumbent, branching occasionally

Procumbent to erect, dichotomously branching

Rooting at the nodes

Readily

In later summer

Hardly ever

Petiole length (note 1)

Variable but rarely shorter than the shortest leaflet, often much longer

Varying from less than the length of the shortest leaflet to much longer

Variable; leaves near apex of stem may be sub-sessile whilst those nearer the base have much longer petioles

Stipules (note 1)

Simple

Entire or deeply cut

Entire or deeply cut

Leaflet number (note 1)

3, 4 or 5

3, 4 or 5; predominately ternate but some plants have a much higher proportion of 5-nate leaves than others

3 (4 or 5)

Number of petals

4 or 5

4 or 5

4(5)

Fertility

Sterile

Fertile

Partially sterile; a few achenes may be formed

Note 1. Cauline leaves (basal leaves do not always persist).

The reason for the difficulty is that P. anglica arose by hybridisation between P. erecta and P. reptans associated with chromosome doubling, and is therefore intermediate between them in morphology. P. × mixta and P. × suberecta take intermediate positions between their parents so that there is an almost continuous range of morphology from P. erecta at one extreme to P. reptans at the other. The species and hybrids can easily be separated by chromosome counts since P. erecta and P. reptans have 28 chromosomes, P. anglica has 56 and both hybrids have 42, but this is no help to the field botanist.

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Plant Crib The difficulties are exacerbated by environmental variation. For example, plants growing on bare or trampled ground or in short turf develop very small leaves and short petioles. Seasonal variation is also very pronounced, especially in P. anglica and the hybrids, resulting in a progressive decrease in leaf and flower size and a shortening of the petiole throughout the summer. For these reasons quantitative characters are hopelessly unreliable and it may be impossible even for the most experienced observer, to distinguish between P. anglica, P. × mixta and P. × suberecta on morphological characters alone. Fertility is the only certain diagnostic feature. P. anglica is seed- and pollen-fertile but the hybrids are sterile. A plant with intermediate morphology which is setting seed can therefore be confidently identified as P. anglica. Unfortunately seed set cannot be assessed early in the flowering season; as a rough indication of maturity, it should be possible to count at least three withered flowers on the same stem distal to an open flower or bud. The oldest of these flowers heads should contain conspicuously swollen carpels if the plant is fertile. P. × mixta rarely produces even a single achene per flower and P. × suberecta may set a few seeds but undeveloped carpels always outnumber the swollen ones. One word of caution: P. reptans is highly fertile but self-incompatible and therefore needs to be cross-pollinated in order to set seed. Since large areas may be colonised by a single clone which has spread vegetatively, cross-pollination sometimes does not occur resulting in the absence of seed. A plant should not be identified as a hybrid unless it also shows the mixture of 3-, 4- and 5-nate leaves and 4- and 5-nate flowers typical of the hybrids. Leaflet shape is too variable to be diagnostic although leaflets of P. anglica tend to be more broadly obovate than those of the hybrids and in P. × mixta the teeth tend to occur nearer the leaf base. The flower diameter is also too variable to be diagnostic and it diminishes throughout the flowering season. P. anglica and the hybrids have small simple leaves like a single leaflet (arrowed on the drawings) as well as palmate leaves; if confused with the stipules, these will give rise to errors since the large stipules of P. erecta and P. × suberecta are an important diagnostic feature. The third possible hybrid combination, P. erecta × P. reptans, has 28 chromosomes but only one natural hybrid with this chromosome number has so far been found. It must therefore be very rare. Plants which are sterile, similar to P. anglica in morphology but more delicate or smaller and with narrower leaflets should, if possible, be collected live and grown for further examination. This does not mean uprooting the plant; runners will usually root readily in water. When collecting specimens for determination, please collect a complete stem or stems with at least three withered flowers behind the open flower or bud so that seed set can be assessed, and describe the range of petal number on a plant. References M atfield, B., Jones, J. K. & Ellis, J. R. (1970). New Phytologist 69: 171-186. M atfield, B. & Ellis, J. R. (1972). Heredity 29: 315-327. Harold, B. (1994). BSBI News 66: 13-15. Author

B. Harold (née M atfield), February 1988.

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Plant Crib

POTENTILLA STERILIS / FRAGARIA VESCA, VEGETATIVE These two species are readily distinguishable, but are sometimes confused vegetatively. Those relying only on the well-known terminal tooth character may occasionally get caught out if other characters are not also used. Potentilla sterilis (L.) Garcke: Terminal tooth of leaflet usually much smaller and shorter (rarely longer) than adjacent teeth (Fig. a).; leaflets broadly obovate, dull, mid to dark green. Fragaria vesca L.: Terminal tooth of leaflet usually longer than adjacent teeth but sometimes shorter, and usually not much smaller than adjacent teeth (Fig. b); leaves elliptic to obovate, shiny, bright yellowish-green. a

b

Leaflet apices. (a) Potentilla sterilis, (b) Fragaria vesca.

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Plant Crib PTERIDIUM AQUILINUM AGGREGATE Two species of bracken have been recognised in Britain (P. aquilinum and P. pinetorum (P. latiusculum auctt. europ. non Michx.). Page recognises further forms of both species at subspecific rank (Page & Mill 1994; Page 1997) which need further study to ascertain their ultimate taxonomic status. P. pinetorum subsp. osmundaceum (Christ) C.N. Page is a stunted form with broader oblong leaf segments and a superficial likeness to Osmunda and is known from only two populations. Three subspecies are recognised by Page (1997) in the P. aquilinum complex: subsp. aquilinum, the ubiquitous form and the only one that has become an agricultural pest; subsp. atlanticum, characteristic of lowland basic soils in SW Scotland; and subsp. fulvum C. N. Page, so far recorded in only a few sites in central Perthshire. The latter has some similarities in leaf-shape and wiry orange petiole to P. pinetorum and may be a ‘hybrid’ with that taxon. Because each of the segregate taxa in Britain and Ireland have been only recently recognised, it is likely we have as yet a very incomplete picture of their ranges. Further occurrence of P. pinetorum is most likely within areas of present (and past?) native pine woods, especially in Scotland. Stands are most easily spotted in early summer when the nearly synchronous rapid expansion of the angled blades on thin upright petioles causes them to become fully expanded at least two weeks before those of P. aquilinum in the same area. See Figure (c) below, and the Table for further characters. With regard to P. aquilinum subsp. atlanticum, further occurrence (especially in moist base-rich areas around limestone) in milder climates is most likely, and should be sought throughout the western seaboard of Britain and throughout Ireland. At a distance stands are also easily spotted in early summer when the strongly upright leaves with thick succulent petioles show a highly sequenced (‘hypolepoid’) expansion of successive pinna-pairs with flaccid, drooping-tipped pinnules (Fig b). Closer-up the vivid white colour of the dense hairs on the expanding crozier tips compared to the brindled colour of the common P. aquilinum subsp. aquilinum and the long-persistent perpendicular white hairs to the petioles and pinnae rachides are particularly distinctive. The table below compares the characters of P. aquilinum subsp. aquilinum, P. aquilinum subsp. atlanticum, and P. pinetorum. Field photographs and further leaf silhouettes showing the main diagnostic features of all taxa are give in Page (1997) pp. 344370.

‘Fronds’ (leaves) of Pteridium collected at the same time: (a) P. aquilinum subsp. aquilinum; (b) P. aquilinum subsp. atlanticum; (c) P. pinetorum. (adapted from Page 1997).

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Plant Crib Pteridium aquilinum (L.) Kuhn subsp. aquilinum

P. aquilinum subsp. atlanticum C. N. Page

P. pinetorum C.N. Page & R.R. Mill

General habit of plant

Orientation of leaflets variable but mostly twisted as in a venetian blind

Plane of leaflets always markedly twisted as in a venetian blind

Plane of leaflets same as whole leaf which is swept back at c. 30o to the horizontal

Height of plant

(30-) 80-200 cm

(30-) 80-180 cm

30-100 cm

Petiole of compound leaf (stalk of bracken ‘plant’) i.e. young ‘frond’

Green, somewhat succulent-herbaceous, containing mucus, less than 15 mm wide

Green, markedly succulent-herbaceous, containing much mucus, less than 12 mm wide

Orange-red-brown, hard, wiry, with little mucus, c. 7 mm wide

Lower pinnae

Linear-lanceolate, tips ± drooping

Linear-lanceolate, tips flaccid, drooping

Broadly ovate, tips assurgent

Leaf texture

Somewhat coriaceous, ± dull

Relatively soft and dull.

Herbaceous to coriaceous, glossy

Hairs on croziers and underside of young leaves and pinna rachises

Short white hairs interlaced (brindled) with cinnamon coloured or reddish brown hairs which are easy to pick out

White hairs dominant with very few cinnamon or reddish brown hairs, the whole having a silvery appearance; hairs on pinnae rachises spreading and more persistent

White hairs few, redbrown hairs dominant and giving a reddish (cinnamon) hue to the crozier, hairs lost on ageing (and on drying)

Rate of unfurling of leaflets

Typically completed by early summer

Continuation of compound leaf and unfurling of apical leaflets continues well into autumn

Open almost simultaneously throughout frond, completed early in the season

Because of the unwieldy size and carcinogenic nature of all bracken fronds, and their potentially rapid rate of decay at the crozier stage, initial refereeing of unusual finds should first be gained exclusively by use of duplicate colour slides submitted to Chris Page, Gillywood Cottage, Trebost, Stithians, Truro, TR3 7DW. Pressed, thoroughly dried, small pinnae, including a crozier and pinna tip should only be submitted if subsequently requested. References

Page, C. N. (1997). The ferns of Britain and Ireland. Edn 2. Cambridge University Press, Cambridge. Page, C. N. & Mill, R. R. (1994). Botanical Journal of Scotland 47: 139-140.

Authors

C. N. Page & A. C. Jermy, January 1998.

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Plant Crib

QUERCUS

1. Quercus petraea / Q. robur / Q. × rosacea Not only are Q. petraea and Q. robur variable in themselves, but they have also widely introgressed producing variable, fertile hybrids. This results in inconsistent identification of both the parents and their hybrid Q. × rosacea by different botanists as the limits of the species are a matter of opinion. Identification must be made on a COM BINATION of characters. Ideally, mature leaves from the middle of a shoot in the sunny well-lit part of the canopy should be examined. As these leaves are often out of reach, the Table on page 76 summarises the characters for all leaves (and leaf litter). However it is important to note that leaf litter may contain lammas leaves and these generally are atypical. Similarly leaves of seedlings and young plants may not conform to those of the mature tree. M ature peduncle characters may also help from the end of June onwards but length can be very variable even on the same shoot. The Table on page 76 has been compiled from Jones (1959), Cousens (1963), Wigston (1975) and Kelly (1995), and examination of material in CGE and NMW. The illustrations show some of the variation present in Q. petraea, Q. robur and Q. × rosacea drawn from specimens in CGE determined by P. D. Sell. Intercalary veins are comparatively large veins from the midrib to the sinus between two lobes. References Carlisle, A. & Brown, A. H. F. (1965). Watsonia 6:120-127. Cousens, J. E. (1963). Watsonia 5: 273-286. Jones, E. W. (1959). Journal of Ecology 47: 169-222. Rushton, B. S. (1978). Watsonia 12: 81-101. Wigston, D. L. (1975). Watsonia 10: 345-369. Author

B. S. Rushton, October 1997.

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Plant Crib

Illustrations of Quercus leaves (del. M. D. B. Rich)

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Plant Crib Quercus rob ur L.

Quercus × rosacea Bechst.

Quercus petraea (Mattuschka) Liebl.

Leaf lobing

Deep, irregular, finger-like, often with smaller sublobes

Shallow irregular to deep, regular

Shallow, regular, lobes more “triangular”

Mean no. pairs lobes (note 1)

Up to 5 (total range 2-6)

4-6 (total range 37)

5 or more (total range 4-8)

Intercalary veins

Generally present

Variable in number

Absent

Auricles at leaf base

Usually strong

Intermediate

Absent or weak

Hairs under leaf

Stellate hairs absent (simple hairs present)

A few stellate hairs may be present among the simple hairs

Large and small stellate hairs present among the simple hairs, particularly along the midrib and the angles between the midrib and main veins

Petiole

(0-)2-7(-9) mm, c. up to 8% of leaf length

Variable

(7.5-)10-25(-32) mm, c. (7-)10-21% of leaf length

Leaf shape

Oblanceolate with cordate base

Variable

Elliptic or nearly so, with cuneate rarely cordate base to lamina

Mean mature 0-3(-4) cm peduncle length (to first flower)

Variable

2-9 cm

Mature peduncle pubescence

Variable

Pubescent throughout

Glabrous at maturity (hairy when young)

Note 1. Count lobes on both sides, divide by two and discount any halves.

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Plant Crib 2. Quercus cerris Quercus cerris L. is now widely established across much of southern Britain. The variable nature of its leaves (cf. illustrations) mean that detecting hybrids with Q. robur is not straight forward, if they occur at all (A. Coombes, pers. comm. 1998). The few potential examples examined by TCGR have sparsely pubescent underside to the leaf, more lobes often with small teeth and cups with small scales, but this may be part of the variation in Q. cerris. Potential hybrid specimens, preferably with acorns, to A. Coombes please.

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Plant Crib

RANUNCULUS

1. Ranunculus acris R. acris L. is represented in the British Isles by subsp. acris, within which three varieties can be recognised (Coles 1971). The distribution of the taxa is not known with certainty. Descriptions of the leaves refer to spring leaves, i.e. those produced just before the first flowering stem of the year. 1

Leaves produced before the first flowering stem of the year glabrous (i.e. look at oldest leaves which persist; those produced later may be hairy); leaves usually shallowly lobed, never finely divided (Figs. c, d). Cairngorms, mainly confined to snow patches in the mountains

1

Leaves hairy, variously divided (Figs. a, b)

2

Hairs on the upper surface of the leaf rarely exceeding 1.2 mm; leaves variously divided, often very finely. Widespread

2

Many hairs on the upper surface of the leaf exceeding 1.2 mm; leaves never finely divided, lobes usually broad. Ireland and Scotland, especially in areas of less intensive agriculture

R. acris subsp. acris var. pumilus Wahlenb. 2 R. acris subsp. acris var. acris

R. acris subsp. acris var. villosus (Drabble) S. M. Coles

Leaves of Ranunculus acris (a, b) var. acris, (c, d) var. pumilus.

Reference

Coles, S. M. (1971). Watsonia 8: 237-261.

2. Ranunculus acris / R. repens / R. bulbosus, non-flowering plants In grazed, closed grassland leaves of the three species can appear very similar. The leaves can be told apart without resorting to digging up plants to see if they have bulbous bases. R. acris L. is very variable (cf. account above) but has evergreen leaves which are typically 5-lobed, and readily separable from the other species. R. bulbosus L. has leaves which mainly appear in the autumn Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib and disappear by early summer after flowering, though a few small ones can sometimes persist through the summer. It is significantly under-recorded due to its early flowering. Compared to R. repens L., its leaves tend to be squarer, the white blotches if present are usually weaker, and the side leaflets are usually joined to the petiole rather than having distinct stalks. R. repens is very variable, and plants may or may not produce runners.

3. Ranunculus lingua / R. flammula Large forms of R. flammula (e.g. var. major Schult., see below) may result in the unwary over-recording R. lingua . There is little doubt that R. lingua is spreading, possibly as a consequence of widespread planting in ponds. They can be distinguished as follows (cf. Stace’s New Flora): R. lingua L.: Flowers 20-50 mm wide; pedicels furrowed; achenes c. 2.5 mm. R. flammula L.: Flowers to 25 mm wide; pedicels smooth; achenes 1-2(-2.3) mm. R. flammula is very variable. Field observations and transplant experiments demonstrate clearly the plasticity of habit, of leaf shape and serration, and of petiole length. With four exceptions (see below), these diverse leaf forms are not correlated with other characters, and most infraspecific taxa based on leaf form alone have little significance (Padmore 1957). Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib R. flammula subsp. flammula var. flammula is widespread (Padmore gives two environmentally-induced phenotypes). R. flammula subsp. flammula var. major is a strikingly large plant which has been confused with R. lingua (cf. above). It occurs mainly the south but has been recorded as far north as Aberdeenshire and in western Ireland. R. flammula subsp. minimus is a dwarf form found in exposed situations near the sea growing in short turf. The distinctive features are the short internodes, thick fleshy leaves and comparatively large flowers. It has been recorded for V.c. 101, 108-112 & H9. R. flammula subsp. scoticus which has readily detachable, very narrow basal leaves which are reduced to awl-shaped petioles alone. Jizz characters, which are not diagnostic, are the slightly zigzag stem, the obtuse lower stem leaves, and the petals which have a cuneate base broadening upwards to a truncate apex so that they appear distant from one another. It has been confirmed from V.c. 88, 94, 96-98, 103105, 108, 110, H17, H26, H27 & H29. Note the stem leaves are usually narrower than the basal leaves (the latter are the most important). The basal leaves tend to increase in size as they are produced. Silverside (1984) gives many useful notes, and the taxa are mapped with notes in Aquatic Plants. 1

Basal leaves reduced to subulate petiole only, caducous (i.e. dropping early); later leaves sub-caducous with a more pronounced short, blunt, linear-oblong blade (Fig. c)

1

Lamina of basal leaves narrowly-lanceolate to wider than long, persistent

2

Lamina of basal leaves of mature plant orbicular or wider than long (Fig. a), distinctly cordate at base; achenes 1.0-1.3(1.4) x as long as wide (note 1); flowers 15 mm or more across; plant fleshy, mat-forming R. flammula subsp. minimus

R. flammula subsp. scoticus (E. S. Marshall) A. R. Clapham 2

(A. Benn.) Padmore 2

Lamina of basal leaves of mature plants lanceolate to broadly ovate, cuneate to rounded at base (Fig. b); achenes 1.151.65 x as long as wide (note 1); flowers 8-25 mm across 3

3

Plant 30-60 cm, robust, erect, rarely rooting at even the lowest node; flowers 18-25 mm across

3

Plant slender, stem ascending or creeping and rooting; flowers 8-20 mm across

R. flammula L. subsp. flammula var. major Schult. R. flammula subsp. flammula var. flammula Notes 1. Silverside (1984) finds this character little use. 2. Intermediates occur.

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Plant Crib

References Marshall, E. S. (1892). Journal of Botany 30: 289-292. Padmore, P. A. (1957). Watsonia 4: 19-27. Silverside, A. J. (1984). BSBI Scottish Newsletter 6: 4-7. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib 4. Ranunculus flammula / R. reptans / R. × levenensis Creeping spearworts recorded from stony lake shores in V.c. 69, 70, 72, 73, 85, 93, 98 and H40 are probably mainly Ranunculus flammula × R. reptans hybrids (Gornall 1987). Pure R. reptans has been recorded in four localities but may not persist (Birse 1997; Aquatic Plants). Plants can usually be distinguished using a combination of characters in the Table below. Unfortunately, most of these characters are highly plastic, and sometimes it can be particularly difficult to tell the hybrid from either procumbent forms of R. flammula or from pure R. reptans without a cultivation experiment, although the achene beak length/achene length ratio is reasonably diagnostic in both cases. Extreme difficulties arise in situations where the hybrid is a product of back-crossing to one parent or where it is a parental type segregate. In such cases there is no easy answer except arbitrarily to treat all variants that fall within the established morphological ranges of the parents as pure species, even if hybrids occur in the same population. Characters used to separate R. × levenensis from its parents are given below. Values quoted are ranges; all measurements have been made on wild-collected, herbarium material. Equivalent data on cultivated plants can be found in Gibbs & Gornall (1976). R. flammula L.

R. flammula L.

R. × levenen-sis Druce ex Gornall

R. reptans L. (note 1)

erect

procumbent

Stem diameter

1-9 mm

1-3.5 mm

0.5-2.8 mm

0.3-1.9 mm

Largest basal leaf, width

1-30 mm

1-20 mm

1-4(-10) mm

0.3-1.5 mm

Largest flower, diameter

6-20.5 mm

5-15 mm

6-12(-15) mm

6-10.8 mm

Width of largest petal 2-8.1 mm

1.1-5.0 mm

1.2-3(-4.5) mm

1.3-3.2 mm

Achene beak length / 6.5-20.6% achene length excluding beak

5.6-19.1%

12.3-28.8%

21.6-29.2%

Note 1. Non-British material. References Birse, E. M. (1997). BSBI News 74: 17-19. Gibbs, P. E. & Gornall, R. J. (1976). New Phytologist 77: 777-785. Gornall, R. J. (1987). Watsonia 16: 383-388. Author R. J. Gornall, 1997. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib 5. Ranunculus ophioglossifolius / R. flammula R. ophioglossifolius is currently only known from two sites in Gloucestershire but could very easily be overlooked as R. flammula elsewhere. It is variable in size depending on the environmental conditions, ranging from small spindly plants only 3 cm tall to robust tall plants of similar size to R. flammula. It occurs in seasonally dry ponds; full details of any new sites of this very rare plant should be recorded. Look for smaller plants with paler yellow flowers amongst R. flammula; be warned, R. flammula is very variable. In cultivation at least, R. ophioglossifolius is a paler yellowish-green with leaves glossy on upper surface. Ranunculus ophioglossifolius Vill.

R. flammula L.

Habit

3-60 cm tall, erect to ascending

10 - 100 cm tall, erect to prostrate

Flower s

Petals separated, not overlapping; canary yellow

Petals overlapping, usually at least at base; golden-yellow

Fruits

Tuberculate

Smooth

Reference

Holland, S. C., ed. (1977). Badgeworth Nature Reserve Handbook. Gloucester Wildlife Trust.

6. Ranunculus ficaria The four subspecies of Ranunculus ficaria L. in Britain have been reviewed by Sell (1994) from which the key below is taken (these are included in Stace’s New Flora 2nd edition 1997). Flower size should be noted on early visits as later flowers tend to be smaller. However, later visits are required to check for development of bulbils and fertile achenes, neither of which have developed at first flowering. Do not confuse the small whitish root tubers for the bulbils in the leaf axils! 1 1

Leaves up to 8 × 9 cm; petioles up to 28 cm; flowers up to 60 mm in diameter; achenes up to 5.0 × 3.5 mm Leaves up to 4 × 4 cm; petioles up to 15 cm; flowers up to 40 mm in diameter; achenes up to 3.5 × 2.2 mm

2 2

Stems rather robust, but straggling; bulbils present in leaf axils after flowering subsp. ficariiformis (F. W. Schultz) Rouy & Foucaud Stems robust and erect; without bulbils in leaf axils after floweringsubsp. chrysocephalus P. D. Sell

3 3

Bulbils not present in leaf axils after flowering; achenes well developed Bulbils present in leaf axils after flowering; achenes not well developedsubsp.

subsp. ficaria bulbilifer Lambinon

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2 3

Plant Crib Subsp. ficariiformis and subsp. chrysocephalus are both relatively rare, but do look different to subsp. ficaria and subsp. bulbilifer as the flowers are significantly larger. Voucher specimens should include measurements of petal length and flower width when open. Subsp. ficaria and subsp. bulbilifer are widespread through Britain, though both are under-recorded. A useful tip for picking up subsp. bulbilifer is to look for large yellowing patches in late spring which are evidently spreading vegetatively. It also occurs in small patches as a weed in gardens, road verges, etc., sometimes as isolated plants. There is considerable variation in flower colour, number of petals, leaf blotching and leaf shape in all subspecies. In addition there are a number of cultivars in gardens with black leaves, double flowers, etc. Similar plants may be found occasionally in the wild, as may cultivated plants which sometimes become established on waste thrown out of gardens; voucher specimens should be collected. Reference

Sell, P. D. (1994). Watsonia 20: 41-50.

7. Ranunculus Subgenus Batrachium

Introduction Within this Subgenus, difficulties with identification arise mainly from extreme phenotypic plasticity, morphological reduction and frequent hybridisation. Most species look very different in summer and winter, and are impossible to identify in the vegetative state. Except for species such as R. hederaceus, R. omiophyllus and R. tripartitus, it is unwise to try to identify plants in winter. Even when good flowering and fruiting material is available it is important to take care to gather an adequate specimen. In heterophyllous species, small apical portions of shoot are inadequate and specimens should include capillary leaves attached 5 or 6 nodes away from the apex. Try to collect mature fruits as well as flowers. The flowers are delicate and soon fall apart, so it may help to keep a few separate so that petals can be measured and stamens counted, but leave some attached to the plant! The most authoritative taxonomic work on the group world-wide is the monograph by Cook (1966). Holmes (1979) used essentially the same characters, and included an important new feature, a tabular summary of the main features of each species (see pages 56-57). This is particularly useful because it often allows incomplete material to be identified, and the whole range of characters for a species can be seen simultaneously. This helps to avoid the frequent problem with a dichotomous key of misidentifying material on account of a single character. The revised tabular key is based on many of the old characters combined with the results of more detailed research. A key to R. peltatus, R. aquatilis, R. fluitans, and subspecies and varieties of R. penicillatus is also given on page 60 in the species accounts (Webster 1991). Hybrids are not included in the keys. However, three hybrids, R. omiophyllus × R. tripartitus, R. peltatus × R. fluitans and R. fluitans × R. trichophyllus and/or R. aquatilis have a distribution which is not strictly limited by the distribution of their parents and brief descriptions are included for these hybrids (pages 63-64).

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Plant Crib R. penicillatus now comprises two subspecies, subsp. penicillatus and subsp. pseudofluitans (Webster 1988). Within subsp. pseudofluitans two varieties are recognised which are sometimes difficult to separate and difficult material should be recorded simply as subsp. pseudofluitans. The new and old names are as follows: New name R. penicillatus subsp. penicillatus R. penicillatus subsp. pseudofluitans var. pseudofluitans R. penicillatus subsp. pseudofluitans var. vertumnus

Old name R. penicillatus var. penicillatus R. penicillatus var. calcareus R. penicillatus var. vertumnus

Many taxonomic problems, to which there are no easy answers, still remain. For example, the hybrid R. omiophyllus × R. tripartitus, which is frequent in the New Forest, includes forms which have arisen from extensive back-crossing and closely resembles R. tripartitus. A second common problem arises with plants that resemble R. baudotii very closely, except that they have hairy carpels, whereas ‘good’ R. baudotii has glabrous fruits. A further problem, and possibly the most frustrating, is the morphological continuity between R. fluitans and R. penicillatus var. pseudofluitans. Holmes (1979) pointed out that forms of var. pseudofluitans resemble R. fluitans in their leaf characters. This places all the more importance on the other main character separating the taxa, namely, the hairiness of the receptacle. Although some receptacles are readily determined as either glabrous (R. fluitans) or distinctly hairy (R. penicillatus var. pseudofluitans), an embarrassing number of receptacles are intermediate. Taxonomic characters LEAVES: characters 1-14 on the tabular key Two kinds of leaf are found within the group; the flat, rounded LAMINAR type, and CAPILLARY leaves which are finely dissected into many capillary segments. In the heterophyllous species, laminar leaves are normally formed in response to specific environmental stimuli, normally the onset of longer photoperiods in summer, acting on the submerged shoot apex. In these species, flower production is not linked to the production of laminar leaves, and flowering can start about a month before the laminar leaves appear. In R. tripartitus the first seedling leaf is always laminar, and the plants continue to produce laminar leaves under warm conditions, irrespective of the day length. Capillary leaves are produced in cold water under short photoperiods, which, in the field, means up to about the middle of March. In heterophyllous species, many plants produce one or two intermediate leaves at the transition between the capillary and laminar leaf types, and these can be helpful in identification (see characters 7-9). LAMINAR LEAVES: characters 1, 3-6 The shape of the laminar leaves is useful taxonomically. R. hederaceus and R. omiophyllus rarely cause any difficulty since R. hederaceus has a very distinctive leaf shape, with the lobes broadest at the base, whereas in all other species, including R. omiophyllus, the lobes are narrowest at the base. In R. tripartitus and R. baudotii the leaves are deeply 3-lobed, whereas R. aquatilis, R. peltatus and R. penicillatus generally have 5 lobes and are more shallowly lobed, although leaves produced under water tend to have deeper sinuses. In R. aquatilis, the leaf margin is dentate, and this is useful to support other characters in distinguishing this species from R. peltatus, in which the margin is normally crenate. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib However, care is needed if leaves of R. peltatus have formed under water or in shade, as these leaves are often dentate. These leaves will look etiolated and have long petioles. In R. penicillatus subsp. penicillatus the leaves may be crenate or dentate. [A simple way of remembering which leaf shapes are which species in R. hederaceus and R. omiophyllus is to remember for the former that the lobes resemble an ‘h’ for hederaceus being widest at the base, and in the latter an ‘o’ for omiophyllus with the lobes widest in the middle.] INTERMEDIATE LEAVES: characters 7-9

Intermediate leaves. (a) radially symmetrical leaves with pointed lobes as in R. tripartitus, (b) radially symmetrical leaves with flattened capillary lobes as in R. baudotii, (c) ‘mosaic’ type leaves with capillary portion proximal as in R. aquatilis, (d) ‘mosaic’ type leaves with capillary portion distal as in R. peltatus and R. penicillatus.

Intermediate leaves are not always formed, but when present, they can be helpful towards identification. R. tripartitus and R. baudotii are the only species that produce radially symmetrical intermediate leaves. In R. tripartitus the lobes are fine and pointed, whereas in R. baudotii they take the form of flattened capillary lobes. In R. aquatilis, R. peltatus and R. penicillatus subsp. penicillatus the intermediate leaves are mosaic in type: parts of the leaf are laminar, and parts capillary. In R. aquatilis, the capillary part is normally proximal (i.e. between the petiole and the laminar part) so that the leaf appears to have stalked lobes, whereas in R. peltatus and R. penicillatus, the capillary part is distal, the tips of the leaf lobes being extended into fine points. In R. penicillatus these capillary appendages can be quite long. As Holmes (1979) points out, this character is not 100% reliable but it can, nevertheless, be useful. Since these patterns are difficult to visualize, they are illustrated below. CAPILLARY LEAVES, AQUATIC FORMS: characters 10-14 R. circinatus stands out on account of its capillary leaves, which are short and rigid, with divergent segments that are held in a single plane, like the spokes of a wheel. (This leaf-shape is less distinctive in winter as the segments become longer and more flaccid). R. tripartitus is unlikely to be confused with

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Plant Crib any other species and has capillary leaves which are extremely fine and hair-like; these leaves spread divergently in water, but are flaccid and collapse when taken out. Of the remaining species, R. baudotii, R. peltatus, R. aquatilis, R. penicillatus var. vertumnus and R. trichophyllus have leaves which are shorter than the corresponding internodes, whilst in R. penicillatus subsp. penicillatus and R. fluitans the leaves are longer than the internodes. In R. penicillatus var. pseudofluitans the leaves may be longer or shorter than the internodes. The rigidity of the segments is also important; R. baudotii, R. trichophyllus and R. penicillatus var. vertumnus normally have leaves with rigid, divergent segments, R. aquatilis, R. peltatus and R. penicillatus var. pseudofluitans have leaves which may be rigid or flaccid, and R. penicillatus subsp. penicillatus and R. fluitans have flaccid leaves with sub-parallel segments. However, these characters must be used with some caution, since the capillary leaves of species such as R. peltatus and R. aquatilis, as well as R. penicillatus subsp. pseudofluitans show a seasonal pattern of variation, the leaves produced in mid-summer being shorter and more rigid than those produced during the autumn, winter and spring. Further, these characters are modified by environmental conditions, and leaves produced in full light and swiftly flowing water are, again, shorter and more rigid than those produced under shaded conditions or in slowly flowing water. It is also important to compare fully expanded leaves and internodes; towards the shoot apex, where the internodes are not fully elongated, the capillary leaves exceed the internodes in most species, thus, specimens consisting only of a short apical portion of shoot cannot be determined. R. penicillatus subsp. pseudofluitans var. pseudofluitans encompasses a wide range of variation in leaf form, and the capillary leaves are critical in separating long, flaccid-leaved plants of var. pseudofluitans from R. fluitans at one end of the range, and short, rigid-leaved plants of var. pseudofluitans from var. vertumnus at the other. The capillary leaves of R. fluitans sometimes reach 500 mm long, and are rarely forked more than four times. Long, flaccid-leaved forms of var. pseudofluitans (frequently produced in response to slowly flowing or shaded water) resemble R. fluitans but normally have leaves which are at least five times forked and have only been recorded as reaching up to 385 mm long. Occasionally, mainly in poor growing conditions, var. pseudofluitans may form leaves which are less than five times forked, and, wherever possible, additional evidence should be sought from the receptacle (character 30) although this, too, is difficult in some cases (cf. above). Var. pseudofluitans also produces forms with short, rigid leaves which are shorter than the internodes, with a large number (often over 300) of divergent segments. These forms are frequently seen in swiftly flowing water in summer, and resemble var. vertumnus. The leaves are obconical and may have a distinctive, untidy appearance when the water is shaken from them. Var. pseudofluitans does, in fact, intergrade with var. vertumnus but ‘good’ var. vertumnus has globose (i.e. spherical) leaves, which are compact and lack the untidy appearance of rigid, divergent var. pseudofluitans. The compact nature of the leaves gives var. vertumnus a distinctive appearance in the field, where it is seen to form dense, rather neat beds, which are always a very dark green. Var. vertumnus has consistently shorter petioles and leaves than var. pseudofluitans and more leaf segments relative to the length of the leaves. Because these characters apply rather specifically to this part of varieties, they have not been included in the tabular key, and instead they are tabulated below. Var. vertumnus is less phenotypically plastic in these characters than var. pseudofluitans in response to environmental conditions such as shading and flow rate, but it is difficult to distinguish from var. pseudofluitans in winter since the leaves then become longer and more flaccid.

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Plant Crib var. vertumnus

var. pseudofluitans

Rigidity

Normally rigid (semi-rigid or flaccid in winter)

Rigid or flaccid

Segment habit

Divergent

Divergent or sub-parallel

Leaf length/internode length 0.3-1.9 ratio

0.6-3.9

Leaf shape when rigid

Globose, compact

Obconical

Segment number

Rarely less than 100, frequently over 400

30-350

Leaf length

30-70mm (to 132mm in winter)

48-385 mm

Petioles

5-15 mm (to 32 mm in winter)

12-148 mm

Number of segments

1.3-9.1 / mm leaf length

0.1-4.4 / mm leaf length

CAPILLARY LEAVES: TERRESTRIAL FORMS When growing on mud, or on top of banks of Ranunculus which rise above the water, species which are capable of forming capillary leaves form small, crisped terrestrial leaves, with relatively long petioles and slightly flattened segments. Not only do these leaves offer virtually no diagnostic characters but the flowers produced by these mud forms are often abnormal for the species, being smaller, and less fertile, than usual. They are therefore impossible to determine reliably.

STIPULES: character 15 The stipules of leaves in bud are similar in all species, and on old shoots they become damaged, so it is important to examine the stipules of the first fully expanded leaf. The stipules of R. hederaceus are strongly pointed whereas those of R. baudotii are very broad and rounded and R. omiophyllus R. circinatus and R. tripartitus are also rounded. However, these species are the more distinctive ones in the group anyway, and the shape of the stipules is difficult to use diagnostically between the remaining species because it is continuously variable and intergrades between species. Cook (1966) regards the degree of adnation of the stipules to the petiole as important, and although this character is not used in the tabular key, it is included in the descriptions.

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Plant Crib

Stipules. (e) R. hederaceus, (f) R. omiophyllus, (g) R. tripartitus, R. penicillatus, (h) R. baudotii, (i) R. peltatus, (j) R. aquatilis, (k) R. trichophyllus, (l) R. circinatus, (m) R. fluitans.

PEDICELS: character 16 The absolute length of the pedicel and its length relative to the petiole of the opposed laminar leaf is important in separating R. aquatilis from species such as R. peltatus, R. penicillatus and R. baudotii. The pedicel tends to elongate when plants are submerged in deep water, particularly in certain strains. However, the pedicel and the petiole of the opposed laminar leaf respond to the same degree so that the ratio of their lengths can still be used. The pedicel is shorter than the opposed laminar leaf (and usually shorter than 50 mm) in R. aquatilis and longer in R. peltatus, R. penicillatus and R. baudotii. In R. baudotii the pedicel is characteristically strongly recurved, although this sometimes occurs in other species. Pedicels bearing undeveloped fruiting heads are frequently elongated, remaining erect, and this can sometimes be an indication of sterility and hybrid origin. SEPALS: characters 17-18 Cook (1966) reported blue-tipped sepals in R. tripartitus and R. baudotii. Since then, Holmes (1979) reported blue-tipped sepals in some plants of R. fluitans, and I have also seen them in R. trichophyllus. In other species, the sepals are green when young, becoming brown at maturity. They have also been reported in R. aquatilis, R. peltatus, R. penicillatus and R. omiophyllus (Messenger 1988). PETALS: characters 19-24 Petal length is an important taxonomic character, although it is slightly difficult to split the ranges for individual species into 3 discreet ranges, so please see also the ranges given for each species. In R. trichophyllus, the petals are non-contiguous at anthesis, a character which is useful in distinguishing this species from R. aquatilis, which it sometimes resembles closely. NECTAR-PITS: characters 22-24

Nectar-pits at anthesis. (n) Lunate or crescent shaped, as in R. hederaceus, R. omiophyllus, R. tripartitus, R. baudotii, R.. trichophyllus, R. circinatus; (o) circular as in R. aquatilis; (p) pyriform or pear-shaped as in R. peltatus, R. penicillatus, R. fluitans. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib Nectar-pit shape is an extremely important character in the group. The developmental sequence leading to the formation of the pyriform (pear-shaped) type passes through lunate (crescent-shaped) and circular phases, and circular nectar-pits become elongated on senescent petals, so it is important to look at recently matured petals (at anthesis) and not at petals in bud or senescent petals. The nectar-pits are best examined with a hand lens, holding the petal flat and looking from above, at right angles to the surface. A lunate pit can often appear circular if it is viewed by looking down the length of the petal, parallel to the surface. Dried petals on herbarium sheets must be rehydrated. STAMEN NUMBER: character 25 Stamen number varies to some extent with plant vigour, and it is therefore unwise to rely on it for determining plants growing in the terrestrial state or in other unfavourable conditions such as deep water or shade. CARPELS: characters 26-28 Carpel number can be a helpful guide, although, as with petal length, it is difficult to divide the ranges into useful classes, so again it is best to refer to the range given in the descriptions. The hairiness of the carpels is critical as R. hederaceus, R. omiophyllus, R. tripartitus and R. baudotii have glabrous carpels, whereas the immature carpels of R. peltatus, R. aquatilis and R. trichophyllus are hairy. The carpels of R. fluitans are frequently glabrescent. It is important to examine immature carpels since hairy carpels lose their hairs as they mature.

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Plant Crib Tabular key to Ranunculus section Batrachium (see also page 51)

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Plant Crib

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Plant Crib

Glabrous, winged carpel of R. baudotii

R. baudotii is the only species which produces carpels with both a dorsal and a ventral wing (see above). The carpels of R. baudotii are not always winged, but when present, the wings are a good indicator of R. baudotii. Beware specimens of other species which have been gathered and dried when the fruit is immature, since on these specimens the seed fails to develop fully and shrinks within the carpel, giving the appearance of wings. RECEPTACLE: characters 29-30 In R. baudotii, the receptacle elongates in fruit, whereas in other, closely related species, such as R. peltatus and R. aquatilis, it remains globose (Figs. q, r). This is a further good indicator of R. baudotii. Receptacle hairiness is important in distinguishing R. tripartitus (in which it is hairy) from R. omiophyllus (in which it is glabrous), and in distinguishing R. penicillatus var. pseudofluitans, in which it is densely hairy, from R. fluitans in which it is glabrous or sparsely hairy (Figs. s, t). It is important to remove at least some of the carpels to see this character.

Receptacles. (q) elongated receptacle of R. baudotii, (r) globose receptacle as in R. aquatilis, R. trichophyllus, R. peltatus, (s) sparsely hairy receptacle of R. fluitans, (t) densely hairy receptacle of R. penicillatus.

The problem arises in distinguishing between sparsely and densely hairy receptacles. Very few specimens of R. fluitans have completely glabrous receptacles. As a rough guide, if the receptacle is only sparsely hairy, the surface of the receptacle can be seen, complete with achene scars, whilst the surface of a densely hairy receptacle is obscured by the hairs. It is important to be aware that there are some plants with genuinely intermediate receptacles and these probably represent less-than-pure Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib R. fluitans proper so plants with intermediate receptacles should not be recorded under this name. Descriptions and ecological notes

Except in R. penicillatus, where detailed measurements have been made, these largely follow Cook (1966). Maps of all species are given in Aquatic Plants. R. hederaceus L. Prostrate annual or perennial. Leaves laminar, opposite or alternate; stipules ovate, adnate to petiole for more than half their length, apex acute; petiole 2-4 times as long as lamina; lamina 4-25 mm long, 3-35 mm wide, reniform to subcordate with 3, 5 or rarely 7 lobes; lobes broadest at base; margin entire or crenulate. Pedicels in fruit more or less equal to petioles of opposed leaves. Sepals (1-)2-2.5(-3) mm long, spreading. Petals (1.25-)2.5-3.5(-4.25) mm long, ovate, not contiguous; nectar-pits lunate. Stamens (4-)7-10(-11). Carpels (9-)18-24(-42), glabrous; style lateral to subterminal. Receptacle glabrous. More or less throughout Britain and Ireland. On wet mud in small streams, ditches and ponds, often in temporary water and usually in somewhat open and disturbed habitats. R. hederaceus grows in very similar habitats to R. omiophyllus, although it may show a preference for more base-rich and eutrophic habitats. R. omiophyllus Ten. Prostrate annual or perennial. Leaves laminar, opposite or alternate; stipules ovate, adnate to petiole for half their length or less, apex obtuse; petiole 3-6 times as long as lamina; lamina 2-26 mm long, 3-32 mm wide, reniform to suborbicular with 3, 5 or rarely 7 lobes; lobes narrowest at base; margin crenate. Pedicels in fruit equal to or less than petioles of opposed leaves. Sepals (1.75-)2.5-3(-3.75) mm long, reflexed. Petals (3.75-)5-6(-7) mm long, ovate, not contiguous; nectar-pits lunate. Stamens (5-)7-10(13). Carpels (15-)20-50(-67), glabrous; style terminal. Receptacle glabrous. The limits of distribution of R. omiophyllus closely follow the August 7.5 cm isohyetal, and it is absent from much of the drier areas of central and eastern England, northern Scotland and central and Northern Ireland. In similar habitats to R. hederaceus; on wet mud, in small streams, ditches and ponds, often in temporary water and open and disturbed habitats. It may grow in slightly more peaty, base-poor, oligotrophic habitats than R. hederaceus. R. tripartitus DC. Annual or perennial, prostrate in terrestrial state or spreading-erect under water. Leaves laminar or divided into capillary segments. Laminar leaves opposite or alternate; stipules suborbicular, adnate to petiole for more than two thirds their length, apex obtuse; petiole (10-)20-30(-70) mm long; lamina up to 40 mm wide, reniform to suborbicular, deeply 3- or rarely 5-lobed; lobes cuneate, distant, margin entire or crenate. Capillary leaves confined to lower nodes or lacking, alternate; petiole 1-10 mm long; lamina 10-40 mm long, globoid to obconical; segments extremely fine, flaccid. Pedicels in fruit equal to or slightly shorter than petioles of the opposite laminar leaves. Sepals 1-3 mm long, reflexed, caducous, usually blue-tipped. Petals 1.25-4.5 mm long, ovate to slightly obovate, not contiguous; nectar-pits lunate. Stamens (1-)5-8(-10). Carpels 4-27, glabrous; style subterminal. Receptacle hairy. Nationally Scarce. On wet cart tracks, in ditches, temporary ponds and peaty pools. In the field, R. tripartitus behaves as a winter annual; it starts flowering in March and usually dies during April or May, perhaps due to inability to compete with later growing aquatic plants. Since 1930, R. tripartitus has Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib been recorded from 19 10-km squares (Scarce Plants) and old many sites need reconfirming (please note full details and population sizes). It is almost certainly declining, and listed on the Short List of the Biodiversity Steering Group report. R. baudotii Godr. Annual or perennial, prostrate in terrestrial state or spreading-erect under water. Leaves laminar or divided into capillary segments. Laminar leaves occasionally lacking, alternate; stipules suborbicular to orbicular, adnate to petiole for more or less than half their length, apex obtuse; often truncate at base, deeply 3- or rarely 5-lobed; lobes cuneate, sinus more than two thirds as long as lobe; margin crenate or rarely dentate. Capillary leaves always present, alternate; petiole 5-20 mm long; lamina obconical to subglobose; segments rigid, divergent. Leaves intermediate between laminar and capillary occasionally present. Pedicels in fruit longer than petiole of opposed laminar leaf. Sepals 2.5-4.5 mm long spreading or reflexed, usually blue-tipped. Petals 5.5-10 mm long, broadly obovate, contiguous during anthesis; nectar-pits lunate. Stamens 10-20. Carpels (16-)33-39(-60), glabrous, frequently winged when dry. Receptacle hairy, elongating in fruit. R. baudotii has been recorded from 186 10-km squares in Britain and Ireland since 1970, mainly in coastal districts, but also inland near salt deposits (Scarce Plants). In still or slowly flowing, usually brackish, water. Often found in borrow-dykes behind sea walls, in the ditches of coastal grazing marshes, and in temporary pools. Usually in open and disturbed habitats.

Key to R. peltatus, R. aquatilis, R. fluitans, and subspecies and varieties of R. penicillatus (Webster 1991) 1 1

2

Plants heterophyllous - capillary leaves produced all the year round, submerged shoots producing laminar leaves during the summer in response to long photoperiods 2 Plants homophyllous - capillary leaves produced all year round, laminar leaves never produced even by submerged shoots in summer; capillary leaves sorter than, equalling or exceeding corresponding internodes on mature stems; leaf segments rigid or flaccid, divergent or sub-parallel 4 Capillary leaves exceeding corresponding internodes on mature stems; leaf segments flaccid, sub-parallel

subsp.

penicillatus var. penicillatus 2

Capillary leaves shorter than internodes on mature stem (becoming longer than internodes in summer); leaf segments rigid, with divergent segments (becoming flaccid and sub-parallel in winter)

3 3 3

4 4

5

Laminar leaves normally dentate; pedicel in fruit shorter than petiole of opposed laminar leaf and normally shorter than 50 mm; petals 5-10 mm; nectar-pits circular R. aquatilis Laminar leaves normally crenate; pedicel in fruit longer than the petiole of the opposed laminar leaf and normally longer than 50 mm; petals 10-20 mm; nectar pits pyriform R. peltatus Leaves invariably flaccid, and longer than the internodes; leaves never more than four times divided; receptacle glabrous, or only sparsely pubescent R. fluitans Leaves rigid or flaccid, shorter than, equalling, or exceeding internodes; leaves normally at least six times divided; receptacle densely hairy 5 Leaves rigid or flaccid; segments 30-350, divergent or sub-parallel; leaf shape obconical whether rigid or flaccid, rigid leaves having an untidy appearance; leaves 48-385 mm, shorter than, equalling, or exceeding corresponding internode on mature stems and occasionally up to four times its length; petioles 12-148 mm long subsp. pseudofluitans var.

pseudofluitans

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Plant Crib 5

Leaves normally rigid (semi-rigid or flaccid in winter), with divergent segments; segments rarely less than 100, frequently exceeding 400, and occasionally over 900; leaf shape when rigid invariably globose or reniform, leaves becoming obconical only when flaccid; leaves normally 30-70 mm, occasionally up to 132 mm in winter, usually shorter than the corresponding internode and never exceeding twice their length; petioles 5-15 mm, rarely to 20 mm (up to 32 mm in winter)

subsp. pseudofluitans var. vertumnus R. peltatus Schrank Annual or perennial, caespitose in terrestrial state or spreading-erect under water. Leaves laminar or divided into capillary segments. Laminar 1eaves occasionally lacking, alternate; stipules oblong to triangular, adnate to petiole for three quarters of their length or more, apex obtuse; petioles rarely exceeding 70 mm long; lamina up to 40 mm wide, reniform to orbicular, occasionally 3- or 7-lobed; lobes broadly cuneate, sinus usually less than two thirds the length of the lamina; margin crenate. Capillary leaves mostly present, alternate; petiole 5-25 mm long; lamina globose to obconical; segments rigid or flaccid, divergent. Leaves intermediate between laminar and capillary rare. Pedicels in fruit rarely less than 50 mm long, longer than petiole of opposed laminar leaf. Sepals 3-6 mm long, spreading, caducous. Petals (9-)12-15(-21) mm long, broadly obovate, contiguous during anthesis; nectar-pits elongate, more or less pyriform. Stamens 15-30. Carpels (25-)30-40(-80), hairy when immature, occasionally glabrous when mature; style lateral to subterminal. Receptacle hairy, remaining globose in fruit. Distributed throughout most of Britain and Ireland, but absent from much of Scotland and parts of Wales and Ireland. Often found in temporary or disturbed aquatic habitats such as ponds, drainage ditches, newly dug pits, slowly flowing canals, and small streams, but also in more permanent water in larger streams and small rivers. Often found near the source of chalk streams in habitats which dry out for part of the year, where R. penicillatus subsp. pseudofluitans is at a competitive disadvantage. R. aquatilis L. Annual or perennial, caespitose in terrestrial state or spreading-erect under water. Leaves laminar or divided into capillary segments. Laminar leaves occasionally lacking, alternate; stipules triangular, adnate to petiole for three quarters or more their length; petiole up to 90 mm long; lamina up to 30 mm wide, reniform to orbicular, 5- or occasionally 3- or 7-lobed; lobes broadly cuneate, sinus usually less than two thirds the length of the lamina; margin dentate. Capillary leaves invariably present, alternate; petiole up to 25 mm long; lamina globoid; segments rigid or flaccid, divergent. Leaves intermediate between laminar and capillary rare. Pedicels in fruit rarely exceeding 50 mm, shorter than the petiole of the opposed laminar leaf. Sepals 3-5 mm long. spreading, caducous. Petals 5-10 mm long, broadly obovate, contiguous during anthesis; nectar-pits circular, more or less cup-shaped. Stamens 14-22. Carpels (21)32-36(49) hairy when immature, occasionally glabrous when mature; style subterminal. Receptacle hairy, remaining globose in fruit. R. aquatilis probably occurs throughout much of Britain, becoming scarcer in Scotland and from the Irish midlands westwards to County Mayo (Aquatic Plants). However, the name was previously loosely applied, and records must be based on R. aquatilis sensu stricto. Often in similar habitats to R. peltatus, i.e. temporary or disturbed aquatic habitats including ponds, ditches and streams, but the two species have not, apparently, been recorded growing together. R. aquatilis is less a plant of streams and more a plant of pools than R. peltatus, and has often been recorded from farm ponds, indicating that it may prefer more eutrophic habitats.

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Plant Crib R. penicillatus (Dumort.) Bab. Long-lived perennial, stem up to 3 m long in flowing water. Capillary leaves invariably present; laminar leaves present or absent. Stipules suborbicular to ovate, adnate to petiole for three quarters or more of their length. Capillary leaves shorter than, equalling, or exceeding corresponding internode on mature stem; petiole 5-148 mm long; lamina elongate-obconical to globose, 23-284 mm long; segments (26)100-934, rigid or flaccid, sub-parallel or divergent. Pedicel in fruit 50-100 mm long. Sepals 3-7 mm long, spreading. Petals (5-)10-15(-22) mm long, broadly obovate, contiguous during anthesis; nectar-pits elongate, more or less pyriform. Stamens (8-)20-40. Carpels (15-)50-80, hairy or glabrous; style lateral to subterminal. Receptacle distinctly hairy, remaining globose in fruit. a) R. penicillatus subsp. penicillatus Laminar leaves alternate when present; petiole 50-100 mm long; lamina up to 46 mm wide and 25 mm long, reniform to suborbicular, occasionally cuneate at base, 3- or 5-lobed; lobes cuneate, sinus two thirds the length of the lamina or less. Margin of lobes entire, crenate or dentate, frequently with capillary appendages. Capillary leaves invariably flaccid, exceeding the corresponding internode on mature stem; petiole 5-60 mm long; lamina elongate-obconical, 70-215 mm long, segments 100-150, sub-parallel. Pedicel in fruit usually longer than petiole of opposed laminar leaf. R. penicillatus subsp. penicillatus has a western distribution in Britain and Ireland, and is not a common plant (Aquatic Plants). It generally occurs over base-poor rocks although in the Irish midlands, it also occurs over carboniferous limestone. The rivers which subsp. penicillatus occupies in Britain are basepoor, but in Ireland it spreads into more base-rich habitats, perhaps due to the general absence of competition from subsp. pseudofluitans. R. penicillatus subsp. penicillatus usually grows in rivers, but it is also capable of growing in streams, ditches, loughs and the Grand Canal in Dublin. b) R. penicillatus subsp. pseudofluitans (Syme) S. D. Webster Laminar leaves invariably lacking. Both varieties within subsp. pseudofluitans are found in rivers and streams mainly over calcareous or base-rich substrates. Both have a centre of distribution in southern England, becoming scarcer further north. (See Table above under Capillary leaves for comparison) i) R. penicillatus subsp. pseudofluitans var. pseudofluitans (Syme) S. D. Webster Capillary leaves shorter than, equalling or exceeding the corresponding internode on mature stem; petiole 12-148 mm long; lamina elongate-obconical, 50-284 mm long, segments occasionally as few as 26 in winter and in poor growth conditions, but normally 70-347, rigid or flaccid, sub-parallel or divergent. Var. pseudofluitans is widely distributed throughout Britain but there is only one Irish record, from County Antrim, V.c. H39 (Webster 1991; Aquatic Plants). It occurs mainly in rivers and streams, but it has also occasionally been reported from ditches, pools and lakes and, once, from a canal. Like subsp. penicillatus, var. pseudofluitans is frequently the dominant macrophyte over large stretches of river. The rivers which var. pseudofluitans occupies are generally base-rich, but it occasionally occurs in less baserich rivers, notably the Tweed and the Usk. ii) R. penicillatus subsp. pseudofluitans var. vertumnus C. D. K. Cook Capillary leaves normally shorter, and never exceeding twice the length of the corresponding internode on mature stem; petiole 5-32 mm long; lamina globose when rigid becoming obconical when flaccid, normally 23-70 mm long, but occasionally reaching 105 mm in winter. Segments 100-934, normally rigid and divergent, becoming flaccid during winter months and in shaded conditions. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib Var. vertumnus has a similar distribution to var. pseudofluitans but it is scarcer and more local throughout the distributional range and records from Scotland and Ireland are completely lacking. Like var. pseudofluitans, in southern England var. vertumnus occurs principally over chalk, and also over other, mainly base-rich, substrates. Further north it occurs over Carboniferous Limestone and New Red Sandstone. Var. vertumnus is occasionally found growing side by side with var. pseudofluitans, and the two varieties have frequently been recorded from the same river system. However, they appear to have different ecological ranges; var. vertumnus has been more frequently recorded from smaller streams and canals, pools and ditches, and its ecological range may be determined more by a requirement for clear, rather than flowing, water. R. trichophyllus Chaix Annual or perennial, caespitose in terrestrial state or spreading-erect under water. Leaves divided into capillary segments, laminar leaves absent; stipules oblong to ovate, adnate to petiole for two thirds or more their length; petiole up to 40 mm long; lamina globose to obconical; segments rigid or flaccid, divergent. Pedicels in fruit 11-48 mm long. Sepals 2.5-3.5 mm long, spreading, caducous. Petals 3.5-5.5 mm long, ovate to obovate, not contiguous during anthesis; nectar-pits lunate. Stamens 9-15. Carpels 1633, hairy when immature, occasionally glabrous when mature; style subterminal. Receptacle hairy, remaining globose in fruit. Scattered throughout much of Britain and Ireland, but with a centre of distribution in Fenland; becoming scarcer on the south-west peninsula of England, in central Scotland and in the extreme north and south of Ireland. In still or slowly flowing water in temporary or disturbed aquatic habitats such as ponds, ditches or small streams, both in eutrophic and oligotrophic water. R. circinatus Sibth. Long-lived perennial or occasionally annual (Salisbury 1960); stems 5-300 cm. Leaves divided into capillary segments. Laminar leaves absent; stipules ovate, adnate to petiole for three quarters or more their length, apex obtuse; petiole 2-5(-10) mm long; lamina circular to semi-circular; segments rigid, divergent, lying in one plane. Pedicels in fruit 20-100 mm long. Sepals rarely exceeding 6 mm long, spreading. Petals rarely exceeding 10 mm long, obovate, contiguous during anthesis; nectar pits lunate. Stamens (5-)20-24(-27). Carpels (30-)42-48(-56), hairy when immature, occasionally glabrous when mature; style lateral. Receptacle hairy. R. circinatus is mainly found in southern, central, and eastern England, with progressively fewer records in Wales and further north. It is scarce in Ireland. It is found in areas of permanent water in lakes, gravel pits and slowly flowing rivers and canals. It is usually found in eutrophic waters but is occasionally found in oligotrophic conditions, normally in water 1-3 m deep. R. fluitans Lam. Since this is a highly plastic species separate descriptions of the aquatic arid terrestrial states were given by Cook (1966). AQUATIC STATE: Long-lived perennial; stems up to 6 m long, internodes up to 35 cm long. Leaves divided into capillary segments, rarely less than 8 cm long, laminar leaves absent; stipules oblong to ovate, adnate to petiole for three quarters of their length or more; petiole up to 220 mm long (usually long in winter and short in summer); lamina up to 250 mm long, elongate-obconical; segments few, very long, firm, sub-parallel, rarely more than 4 times forked. Pedicel in fruit 40-100 mm long. Sepals 4-6.5 mm long, spreading. Petals 5-10, 7-13 mm long, broadly obovate, contiguous during anthesis; nectar pits elongate-ovate to pyriform. Stamens 20-35. Carpels 34-63, sparsely pubescent when immature, frequently glabrous when mature; style lateral. Receptacle glabrous or very nearly so. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib TERRESTRIAL STATE: Annual, rarely exceeding 60 mm tall, internodes 0.5-10 mm long. Leaves divided into capillary segments 15-45 mm long; segments rigid, sub-parallel, distinctly flattened, often apiculate at the tips. Flowers very rare, similar but smaller than aquatic state, almost invariably sterile. R. fluitans is usually found in permanently flowing water but occasionally colonizes almost stationary water in large drainage ditches where it rarely flowers. It requires a fairly stable substratum and is normally confined to larger rivers with pebble-covered bottoms. Holmes (1979) states that pure forms of R. fluitans are known only from England, E Wales and one site in Northern Ireland. In England, it has a mainly central and northern distribution but is also found in the southern counties. Holmes (1979) has reported that R. fluitans is intolerant of pollution and has declined in abundance, often being replaced by the more resilient Potamogeton pectinatus. Thus, there is a need for existing records to be re-assessed as it may be rarer than was previously thought. Hybrids Accounts largely follow Cook (1975), but see also Webster (1986, 1990). R. × bachii Wirtgen (R. fluitans × R. trichophyllus or R. aquatilis) It is not possible to distinguish between R. fluitans × R. trichophyllus and R. fluitans × R. aquatilis. The hybrids are similar to R. penicillatus subsp. pseudofluitans but are highly sterile and have capillary leaves with a distinctly aberrant appearance, often with rather few, short, capillary segments. The hybrids spread vegetatively. They are almost confined to flowing water and have replaced R. fluitans in several river systems (map in Aquatic Plants). R. fluitans × R. trichophyllus is triploid (2n=24) and R. fluitans × R. aquatilis pentaploid (2n= 40). Parts of the R. penicillatus group (probably R. penicillatus subsp. pseudofluitans) are thought to be derived from these hybrids or similar plants. R. × kelchoensis S. D. Webster (R. fluitans × R. peltatus) This hybrid is morphologically intermediate between both parents except that the receptacle is hairy and that it develops some leaves that are intermediate between laminar and capillary. In summer, it develops some laminar leaves that resemble those of R. peltatus. It is very robust (Usually rather larger than either parent) and is sterile. It has been recorded in V.c. 4, 32, 36, 53, 55, 57, 68, 69, 80, 81 & H39. The hybrid spreads vegetatively and is capable of replacing its parent species. It is pentaploid (2n=40), and this hybrid, or plants like it, are thought to have given rise to some members of the R. penicillatus group (probably in subsp. penicillatus).

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Plant Crib R. × novae-forestae S. D. Webster (R. omiophyllus × R. tripartitus) This hybrid resembles R. tripartitus, except that the petals are up to 6 mm, the pedicel remains erect at maturity and the laminar leaves are frequently five-lobed with shallower sinuses and curved lobes. The plants frequently lack capillary leaves, and when these are present they consist of somewhat flattened, non-collapsing segments. Populations of this hybrid grow independently of the parents at a number of localities in the New Forest (particularly near Brockenhurst, Holmsley, Setley, Boldre, Beaulieu and Hatchet Pond) and possibly elsewhere in Britain (pers. comm. R. V. Lansdown, 1998). Populations are heterogeneous and include the products of selfing and back-crossing, some of which are impossible to distinguish from R. tripartitus. Populations which have been sampled have been shown to be pentaploid (2n=40) and it is thought that they may reproduce agamospermously. Fertility varies from about 7% to about 60%.

Silhouettes of Ranunculus leaves (del. R. V. Lansdown, 1997)

References Cook, C. D. K. (1966). Mitt. bot. Staatssamml., Münch. 6: 47-237. Cook, C. D. K. (1975). Ranunculus subgenus Batrachium. In: Hybridisation and the flora of the British Isles, edited by C.A. Stace. London. Haslam, S. M. & Wolseley, P. A. (1981). River vegetation; its identification, assessment and management. Cambridge. Holmes, N. T. H. (1979). A guide to the identification of Batrachium Ranunculus species of Britain. Chief Scientist's Team Notes 14. London, Nature Conservancy Council. Messenger, G. (1988). BSBI News 49: 14-15. Salisbury, E. J. (1960). Kew Bulletin 14: 34-36. Webster, S. D. (1986). Watsonia 16: 25-30. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib Webster, S. D. (1988). Watsonia 17: 1-22. Webster, S. D. (1990). Watsonia 18: 139-146. Webster, S. D. (1991). Irish Naturalists’ Journal 23: 346-354. Author

S. D. Webster, February 1988, minor updates T. C. G. Rich, 1997.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib

RIBES

1. Ribes, vegetative The British species of subgenus Ribes can be difficult to identify from sterile material. Leaf outlines for each species are given below, but leaf characters, including size, lobing, toothing, sinus-shape and indumentum vary much more than is apparent from most descriptions. Consistent characters are provided by the glands on the leaves and petioles, and for R. nigrum and R. sanguineum by the scent of the crushed foliage. R. rubrum and R. spicatum cannot be reliably separated using vegetative characters (see below), as they have similar glands, and the “typical” leaf type of each species is often found in the other; some garden cultivars may be R. rubrum × R. spicatum. The yellow-flowered introduction R. odoratum (R. aureum auct.) is separable from the other species by the shape and colour of the leaves. Garden plants which look like R. sanguineum Pursh but with larger yellowish-pinkish flowers may be R. × gordonianum Lemaire, and should be collected for verification.

1 1

Plant with spines (sparsely spiny plants can be conf used with R. alpinum!) Plant without spines

2

Glands on leav es and petioles amber (colour may be dif f icult to see)

R. uva-crispa L. (Subgenus Ribes) 2

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 2 Glands on leav es and petioles red

Authors

J. R. Press, J. M . M ullin and M . J. Short, February 1988, minor updates 1998.

2. Ribes spicatum / R. rubrum Although the leaves of the two segregates differ, it is unsafe without much experience, to separate them on leaf-shape alone. Even then, the full spectrum of leaves on any plant should be taken into account. R. spicatum Robson: Inflorescence upright at first, spreading or arching in flower; receptacle perfectly circular (Fig. b), without a raised rim - in section deeply-concave; anther connective-tissue very narrow on inner side, broader on outer side (Fig. a). Scarce calcicole of woodlands and limestone pavement. R. rubrum L.: Inflorescence drooping; receptacle obscurely pentagonal with a raised rim around the style - in section shallowly-concave (Fig. d); anther connective-tissue broad (Fig. c). Widespread. The drawings in S. Ross-Craig Drawings of British Plants are good, except that the receptacle of R. rubrum is not always as clearly pentagonal as she drew. The anther connective character is diagnostic in fresh material.

a

b

c

d

Ribes spicatum (a) anthers (b) flower, R. rubrum (c ) anther (d) flower.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 3. Ribes uva-crispa Research is needed in Britain to see if the distribution of the cultivated forms of R. uva-crispa L. can be distinguished from native forms; please record habitats and likely source of introduction for the following two forms: Possible native form: Berries with short, dense, patent non-glandular hairs. Garden forms: Berries with mixture of long glandular hairs and short hairs, or glabrous.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib

RUBUS Brambles of the British Isles (Edees & Newton 1988) is the essential text, but the following notes have been prepared to aid botanists tempted to take up a study of the genus. Identification difficulties are due to: i) The large number of named taxa, c. 325, in the British Isles and perhaps 200 or more forms which remain unidentified or undescribed. Given this situation it is not surprising that it is necessary in most cases to collect material to confirm identity. ii) The occasional occurrence of hybrids where vigorous bramble growth has followed coppicing, felling or other disturbance. iii) The fact that bushes of different species often grow intermingled, making collection of representative material of the individual species more problematical. Collection of specimens Duplicate collections are usually required (retain one, send the other for naming), unless material has been identified in the field by an expert. i) If it is at all possible, material should be selected from a sunny but sheltered spot; 'normal' characters should then be exhibited. Exposure to the sun is required for expression of pigments in stem and stigmas, often useful characters for identification, but specimens from deep shade will have any secondary armature (pricklets, acicles, etc.) largely suppressed; panicles are also likely to be abnormal. Plants grown in very exposed conditions are sometimes dwarfed, armature is more heteracanth than usual and petals are often bleached. ii) A piece of primo-cane (barren stem) is required with at least one leaf or preferably two or three attached (more, if leaves are variable) (see Figure on next page). iii) Part of a flowering branch from the same bush is required (see below), with a typical panicle which has examples of flower in bud, open, and with the petals dropped and carpels are just beginning to swell. Under certain conditions a primo-cane will develop an elaborate panicle at its tip or send out secondary barren branches; these are usually abnormal and should be avoided. iv) A few petals should be pressed separately and notes taken of colour of petals in bud and expanded, and of filaments and styles. It is also a good idea to check what sort of indumentum appears on the developing carpels. This can be done when laying out the specimen; a flower should be chosen that has recently dropped its petals and the stamens removed from one side, which should reveal the young carpels with styles still attached. If the styles have already dropped off then it is likely that any hairs present will also have done so.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib Pressing specimens Brambles are fairly easy to press as long as attention is paid to their 3-D nature. Care must be taken with short-stalked leaves, especially basal leaflets. It is not advisable to let leaves overlap with pieces of stem or panicle as the leaves are likely to be damaged or poorly pressed. There are at least three approaches to solving this problem, but all have disadvantages : i) Leave stem piece dangling outside press. This ensures leaves are adequately pressed and the stem still exhibits its natural structure, but there is the danger that prickles will be snagged on something and the stem detached from its leaf (which may be difficult to relocate). ii) Leave stem in press and apply sufficient pressure to ensure leaves are sufficiently flattened. This is difficult to judge and may result in crispy leaves or a flattened stem. iii) Leave stem in press and pad leaves with layers of cardboard, wool or drying paper. This can be very effective but pressing and paper changes are more time consuming and less material can go in the press. Ultimately which approach is taken is down to personal preference. A few photographs may be useful to supplement herbarium material. Identification of specimens With the exception of those in Subgenus Rubus, all species native or naturalised in the British Isles are adequately covered in widely available publications (e.g. Stace's New Flora, CTM). There is an excellent account of Subgenus Rubus in Edees & Newton (1988), to which there have been a number of additions since publication, viz. Section Glandulosus Series Sylvatici R. aghadergensis D. E. Allen in Watsonia 20: 61 (1994) R. couchii Rilstone ex D. E. Allen in Watsonia 20: 146 (1994) R. ebudensis A. Newton in Watsonia 17: 173 (1988) R. edeesii H.E. Weber & A. L. Bull in Watsonia 20: 345 (1995) R. gariannensis A. L. Bull in Watsonia 22: 97 (1998) R. waddellii D. E. Allen in Watsonia 22: 83 (1998) Series Rhamnifolii R. cordatifolius (W. M. Rogers ex Ridd.) D. E. Allen in Watsonia 17: 437 (1989) R. davisii D. E. Allen in Watsonia 22: 83 (1998) R. tavensis A. Newton & M. Porter in Watsonia 18: 189 (1990) Series Discolores R. stenopetalus Lef. & P. J. Mueller, A. Newton in Watsonia 18: 89 (1990) Series Vestiti R. caesarius D. E. Allen in Watsonia 20: 145 (1994) R. corbieri Boulay, D. E. Allen in Watsonia 19: 131 (1992) Series Mucronati R. aquarum A. Newton & M. Porter in Watsonia 18: 191 (1990) Series Micantes R. gallofuscus A. Newton & M. Porter in Watsonia 18: 193 (1990) R. percrispus D. E. Allen & R. D. Randall in Watsonia 20: 148 (1994) R. villosior A. L. Bull in Watsonia 22: 100 (1998) Series Anisacanthi R. anglobelgicus D. E. Allen & H. Vannerom in Watsonia 22: 83 (1998) R. biloensis A. Newton & M. Porter in Watsonia 18: 194 (1990) R. cromerensis A. L. Bull in Watsonia 22: 101 (1998) R. metallorum Margetts in L. J. Margetts & K. L. Spurgin, The Cornish Flora Supplement 1981-1990: 107 (1991) Series Radulae R. pannosus P. J. Müll. & Wirtg., A. L. Bull & A. Newton in Watsonia 21: 278 (1997) R. sempernitens D. E. Allen & Margetts in Watsonia 22: 83 (1998) Series Hystrices R. merlini A. Newton & M. Porter in Watsonia 18: 195 (1990) R. segontii A. Newton & M. Porter in Watsonia 20: 140 (1994) R. thyrsigerifomis (Sudre) D. E. Allen in Watsonia 17: 436 (1989) R. venetorum D. E. Allen in Watsonia 22: 83 (1998) Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib Section Corylifolii R. ariconiensis A. Newton & M. Porter in Watsonia 20: 134 (1994) R. hindii A. L. Bull in Watsonia 22: 102 (1998) R. iscanus A. Newton & M. Porter in Watsonia 20: 133 (1994) R. transmarinus D. E. Allen in Watsonia 20: 143 (1994) R. vagensis A. Newton & M. Porter in Watsonia 20: 137 (1994) In addition there have been the following changes in nomenclature: R. canadensis L. is synonymous with R. pergratus Blanch. and has priority. R. armeniacus Focke is R. procerus sensu Edees & A. Newton, Watson et al, non P. J. Mueller ex Boulay. R. asperidens Sudre ex Bouvet has priority over R. milesii A. Newton (D. E. Allen in Watsonia 21: 199 (1996)). R. proiectus A. Beek has priority over R. anglohirtus Edees. Key to Subgenus Rubus The following key is intended to give the beginner an introduction to the genus as an alternative to Edees & Newton (1988), and to indicate the ecological requirements and significance of some of the species. It will not be possible to identify species but combined with one of the reference works it may speed up the identification process. Note that some of the divisions have more than two couplets. Rubus occurs in a wide range of habitats, e.g. open woods, margins of heaths and moors, hedgerows and scrub. Where a particular habitat or soil type is preferred this has been indicated below. The number of species in each group in geographical regions is indicated in brackets. The number of British species recognised in Europe indicates the amount of endemism in each group and their distribution in the regions of the British Isles tends to indicate which groups are better adapted to open ground or the harsher conditions of the north (S. England = V.c. 1-34, Wales/Midlands = V.c. 35-52, N. England = V.c. 53-71). 1

1

1

2

2

Stipules ovate-lanceolate; leaves ternate, not felted beneath; inflorescence corymbose; stamens about equalling styles; styles on lateral flowers often fewer than terminal ones, fruit consequently smaller; drupelets few and large, black but pruinose, only loosely coherent and loosely adherent to receptacle, rarely coming away intact Section Caesii [Dewberry, R. caesius L., frequent on clay, chalk and limestone, also commonly found on grey dunes on the coast. Europe and throughout the British Isles]. In hedgerows hybrids between it and members of Section Glandulosus or Section Corylifolii are often more frequent than the true species. R. × pseudoidaeus (R. idaeus × R. caesius) is often present where the two parents grow in close proximity but is easily passed by as a robust R. caesius. It has prickles rather like R. idaeus and leaves like R. caesius but thinly felted beneath and often pinnate. Fruit is not normally formed. Stipules lanceolate; leaflets usually imbricate, basal leaflets sessile or subsessile; inflorescence often corymbose; stamens often scarcely longer than styles; drupelets few and large, coherent and adherent to the receptacle, coming away intact when ripe, often imperfect; fruit from lateral flowers usually smaller than terminal ones Section Corylifolii [Dewberry-like Blackberries, 23 spp. Common in hedgerows but also in open woods, margins of heaths and moors and in scrub. Channel Isles (Europe) 2(5), S. England 16, Wales/Midlands 17, N. England 10, Ireland 6, Scotland 7] Stipules filiform; leaflets rarely imbricate, basal leaflets stalked, rarely subsessile; inflorescence rarely corymbose; stamens rarely shorter than styles; drupelets numerous, coherent and adherent to the receptacle, coming away intact when ripe; fruit from lateral flowers not much smaller than terminal ones 2 Stems sub-erect, suckering from the roots, rarely rooting at the tip; inflorescence racemose at first, sometimes more elaborate later Section Rubus [Raspberry-like blackberries, 20 spp. Preferring heathy woods and edges of heaths, bogs and moors. Channel Isles (Europe) 1(9), S. England 17, Wales/Midlands 12, N. England 11, Ireland 7, Scotland 4] Stem arching, rarely suckering from the roots but rooting at the tip; inflorescence compound

Section Glandulosus 3 3 3 3 3

Stalked glands absent or rare on stem and inflorescence Stalked glands and acicles absent, rare or sparse on stem, more frequent in inflorescence Stalked glands and/or acicles or pricklets obvious on stem, usually distinct from main prickles Stalked glands, acicles and pricklets frequent to abundant, usually grading into prickles

4 5 6 7

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib 4

4

4

4

5

5

6

6

6

7

7

Leaves green beneath, rarely felted when mature; filaments usually long Series Sylvatici [59 spp. Various habitats on the more acidic soils. Channel Isles (Europe) 2(21), S. England 44, Wales/Midlands 30, N. England 25, Ireland 14, Scotland 9] Leaves greyish-felted beneath; filaments usually long Series Rhamnifolii [42 spp. Mainly hedgerows and scrub, but also open woods, margins of heaths and moors. Channel Isles (Europe) 6(14), S. England 36, Wales/Midlands 24, N. England 15, Ireland 14, Scotland 12] Leaves green or greyish beneath; filaments shorter than styles Series Sprengeliani [4 spp. Heathy woods and edges of heaths, bogs and moors, ancient woodland indicators. Channel Isles (Europe) 1(2), S. England 4, Wales/Midlands 1, N. England 1, Ireland 1, Scotland 1] Leaves silvery- or white-felted beneath; filaments usually long Series Discolores [11 spp. Mainly hedgerows and scrub, but also open woods, margins of heaths and moors. Channel Isles (Europe) 2(5), S. England 10, Wales/Midlands 6, N. England 5, Ireland 3, Scotland 3] Stem moderately to densely hairy, glands often hidden by indumentum Series Vestiti [21 spp. Open woods, margins of heaths and moors, hedgerows and scrub. Channel Isles (Europe) 3(5), S. England 18, Wales/Midlands 14, N. England 7, Ireland 6, Scotland 2] Stem sparsely hairy, stalked glands or acicles more obvious Series Mucronati [11 spp. Open woods, margins of heaths and moors, hedgerows and scrub. Channel Isles (Europe) 0(2), S. England 7, Wales/Midlands 5, N. England 4, Ireland 3, Scotland 3] Acicles and/or pricklets unequal but evenly distributed Series Micantes [29 spp. Open woods, margins of heaths and moors, hedgerows and scrub. Channel Isles (Europe) 2(5), S. England 23, Wales/Midlands 16, N. England 6, Ireland 5, Scotland 1] Acicles and/or pricklets unequal and unevenly distributed Series Anisacanthi [20 spp. Open woods, margins of heaths and moors, scrub, rarely in hedgerows. Channel Isles (Europe) 2(8), S. England 16, Wales/Midlands 13, N. England 9, Ireland 5, Scotland 5] Stalked glands and acicles sub-equal, evenly distributed Series Radulae 42 spp. Open woods, margins of heaths and moors, scrub, less often in hedgerows. Channel Isles (Europe) 2(18), S. England 32, Wales/Midlands 28, N. England 17, Ireland 12, Scotland 6] Prickles strong, pricklets more obvious than acicles and stalked glands Series Hystrices [35 spp. Open woods, margins of heaths and moors, less often in hedgerows and scrub. Channel Isles (Europe) 0(8), S. England 29, Wales/Midlands 17, N. England 9, Ireland 2, Scotland 3] Prickles weak, fine pricklets, acicles and stalked glands abundant Series Glandulosi [7 spp. Forest species, ancient woodland indicators, numerous forms in mainland Europe. Channel Isles (Europe) 0(5), S. England 7, Wales/Midlands 5, N. England 2, Ireland 1, Scotland 0]

Reference

Edees, E. S. & Newton, A. (1988). Brambles of the British Isles Ray Society,

Author

R. D. Randall, January 1998.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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London.

Plant Crib

SALICORNIA AND SARCOCORNIA Salicornia is a very difficult genus (see BSBI News 53: 9-16). Accounts in recent years based on live material (it is usually impossible to identify dried specimens with any reasonable degree of accuracy) cannot be satisfactorily correlated either taxonomically or nomenclaturally, even in NW Europe. Further work is required. A reductionist approach is used here. It should be possible to identify Sarcocornia perennis (Salicornia perennis M ill.), Salicornia pusilla, the diploid Salicornia europaea group and the tetraploid Salicornia procumbens group with reasonable confidence. Beyond this, experience is necessary for accurate determinations. The S. europaea group consists of S. ramosissima, S. europaea and S. obscura. The specific limits within the group are obscure. Inbreeding is probably predominant, and this may account for a great deal of the local variation which occurs. S. ramosissima is very polymorphic and, apart from erect tidal marsh variants of yellow, brownish or purplish suffusion, includes prostrate to decumbent, bright-red variants of saline mud or sand in non-tidal areas behind sea walls, and so far there is no agreement on how to divide it up; names proposed for the British plants (e.g. adpressa, prostrata, smithiana) appear to be invalid and to refer to plants from elsewhere in Europe. M ore experimental work is needed to see if any of the variants described have a genetic basis, or are merely environmental modifications. There is less agreement about the S. procumbens Smith group. S. fragilis here includes S. lutescens P. W. Ball & Tutin and S. emerici Duval-Jouve (Stace’s New Flora includes the latter under S. nitens). S. fragilis itself may be treated as a variety of S. dolichostachya. Voucher specimens are best collected fresh; send several fresh plants in early fruit or later (typically August-September when the coloration has developed best). Photographs showing colour can be invaluable. Permanent collections are best pickled in spirit rather than dried.

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Plant Crib

Fertile segments of Salicornia and Sarcocornia taxa (del. F. Rose).

1

Perennial with creeping rhizomes and some non-f ertile shoots

1

Annual, easily uprooted; all shoots flowering, at least by August

2 2

Cymes 1-flowered (Fig. b) Salicornia pusilla Woods Cy mes 3-f lowered (plants with a mixture of cy mes with 1-3 f lowers are probably S. pusilla × S. ramosissima) 3

3

Anthers 0.2-0.5 mm, of ten not exserted; f ertile segments with conv ex sides, usually strongly beaded (Figs. c-e); lateral f lowers usually distinctly smaller than the central flower

3

Anthers (0.5-)0.6-1 mm, alway s exserted; f ertile segments ± cy lindrical (i.e. straight-sided), sometimes with slightly concave sides (Fig. f ); f lowers equal or subequal in size

Sarcocornia perennis (M ill.) A. J. Scott 2

(Salicornia europaea group) 4 (Salicornia procumbens group) 6 4

Plant deep shining green, becoming more or less reddish-purple or ev en deep rich red; f ruiting segments strongly beaded with strong 'waists' between; scarious margin at apex of each segment broad (c. 0.2 mm) and clearly visible; angle made within apex of segment obtuse, 110-120°, apex of margin obtuse (Fig. d). Very poly morphic, usually much branched, erect to prostrate or decumbent in non-tidal saline areas; mainly in the closed communities of the middle and upper saltmarshes

4

Plant of a lighter, hardly glossy green, remaining that tint or sometimes reddening a little; f ruiting segments only moderately swollen and not beaded or waisted; scarious margin at segment apex v ery narrow and not v ery obv ious, only to 0.1 mm broad 5

5

Plant glaucous-green, matt, nev er reddening (except sometimes a little around the f lowers); erect, primary branches short, scarcely exceeding half the length of the main stem, little branches nev er with tertiary branches; f lowers not markedly unequal in size; scarious margins at apex of segments v ery narrow (0.05 mm) rounded, not f orming a cusp; angle made (if any ) within apex of segment v ery obtuse, 140-150° (Fig. e). On mud or sandy soil in open communities in lower parts of saltmarshes, below the Puccinellia mariti ma zone Salicornia obscura P. W. Ball & Tutin

Salicornia ramosissima Woods

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Plant Crib 5

Plants clear light green, not glaucous, becoming somewhat y ellowish-orange, rosy or red with age; erect or more-or-less prostrate, primary branches of ten as long as the main stem, sometimes with tertiary branches; flowers very unequal in size; scarious margin at apex of segment moderately broad (0.1 mm) f orming a def inite acute, cuspidate point; angle within apex of segment c. 90° or less (Fig. c). On mud or sand, or in wet depressions between sand dunes, mostly in the upper part of saltmarshes with S. ramosissima and in the Puccinellia mariti ma zone Salicornia europaea L.

6

Lower f ertile segments of terminal spike with a minimum diameter 2-3.5 mm; plant usually becoming light brownish- to orange purple Salicornia nitens P. W. Ball & Tutin Lower f ertile segments of terminal spike with a minimum diameter usually exceeding 3.5 mm; plant usually green or y ellowish, rarely pale red or purple 7 Terminal spikes with 6-16(-22) f ertile segments, ± cy lindrical; spikes of the primary lateral branches cy lindrical; plant dull green to y ellowish-green, of ten becoming bright y ellow in f ruit

6 7

Salicornia fragilis P. W. Ball & Tutin 7

Terminal spikes with 12-30 f ertile segments, distinctly tapering towards the apex; spike of the primary lateral branches tapering; plant dark, dull green becoming paler or dull y ellow in f ruit

Salicornia dolichostachya M oss Author

Based on an edited version of F. Rose's September 1984 key by J. R. Akeroyd.

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Plant Crib

SALIX 1. General The BSBI Handbook Willows and Poplars of Great Britain and Ireland by R. D. M eikle (1984) is highly recommended, if not essential, for identification of Salix. Another useful account of identification of the native species in Britain and Ireland with illustrations is given by Howitt & Howitt (1990). Stace’s New Flora includes leaf photographs of most taxa. Problems with the identification of willows will be minimized if material is carefully selected at the right season. Note:1) Juvenile or immature Salix foliage is generally uncharacteristic. Foliage is best collected after midsummer, from July to the end of September. Leaves of some species may be pubescent early in the year but become glabrous later. The rusty hairs on the under-surface of the leaves of S. cinerea subsp. oleifolia may not develop until mid summer. The underside of the leaves of S. fragilis may become more glaucous late in the season. 2) Leaves from sucker or coppice shoots are generally abnormal in all respects and should be avoided. 3) Leaves from specimens growing in shade are usually longer, thinner and more glabrous than is normal; the stipules are often unusually large, and leaves which would normally have contrasting upper and lower surfaces are often uniformly green on both sides. 4) Willows from impoverished and exceptionally exposed sites are commonly dwarfed, often with untypical sprawling branches and small leaves. Such specimens (especially of S. aurita or S. cinerea subsp. oleifolia) are frequently misidentified as S. repens hybrids. Genuine S. repens hybrids generally have an appressed, silky indumentum on the under-surface of the leaf, a character inherited from S. repens. Reference Howitt, R. C. L. & Howitt, B. M . (1990). Willows. In: A guide to some difficult plants. Pp. 28-41. Wild Flower Society, London. 2. Salix aurita, S. caprea, S. cinerea and hybrids

The following leaf illustrations may help with identification of species and hybrids in this complex (material det. E. F. Warburg or R. D. M eikle; OXF). For details of leaf characters please see Willows Handbook or Stace’s New Flora.

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Plant Crib

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Plant Crib

SANGUISORBA MINOR The introduced S. minor Scop. subsp. muricata, once cultivated as a fodder crop and now sown in socalled ‘wild-flower’ mixtures, is widely scattered on roadsides, waste ground etc., in Britain. Subsp. minor is a classic calcicole of plant of chalk and limestone grasslands and occasionally calcareous clays. Tall leafy plants should be examined to see of they are subsp. muricata, as follows: Subsp. minor: False fruits c. 4 mm, angles with thick, not or scarcely sinuate ridges, the faces more or less rugose, reticulate (Fig. a); inflorescences 7-12 mm, sub-globose; leaves mostly basal, cauline leaves few Subsp. muricata (Gremli) Briq.: False fruit c. 6 mm, angles with thin, sinuous wings, the faces with prominent, dentate flanges (Fig. b); inflorescence 10-15 mm, longer than broad; cauline leaves numerous

Sanguisorba minor. (a) subsp. minor, (b) subsp. muricata (del. G. M. S. Easy).

Authors

J. M. Mullin & J. R. Press, March 1988, updated T. C. G. Rich, 1997.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib

SAXIFRAGA Webb, D. A. & Gornall, R. J. (1989). A manual of Saxifrages and their cultivation. (Timber Press, Oregon) is an excellent monograph of the genus which may help with identification. Specimens for identification should include sterile shoots as well as flowers/fruits. 1. Saxifraga rosacea / S. hypnoides / S. cespitosa S. rosacea M oench is currently only known wild in western Ireland, but there is an old record for V.c. 49 (Cwm Idwal) and an unconfirmed record from V.c. 110 (Ben M ore, South Uist). The V.c. 90 record for Glen Doll is now thought to be an error resulting from a mixed collection. It could well occur at other sites, and hence any mossy saxifrages should be checked, especially in Scotland and the northern Pennines (Parker 1979). The tip of the leaf lobe is the most important feature to distinguish S. rosacea from S. hypnoides L.. S. hypnoides has an aristate tip to the leaf lobe, while S. rosacea has an acute to obtuse leaf lobe which may be mucronate but is never aristate. S. hypnoides and S. rosacea both have, almost always, long nonglandular hairs. This contrasts with S. cespitosa which has leaves covered in short glandular hairs. S. cespitosa is protected under the Wildlife and Countryside Act 1981 and must not be collected.

S. hypnoides, mature leaf

Reference

S. rosacea, mature leaf from Clare Island plant

S. rosacea, mature leaf from Burren plant

S. cespitosa, mature leaf

Parker, D. M . (1979). BSBI News 21: 22-23.

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Plant Crib 2. S. hirsuta, S. umbrosa, S. spathularis and their hybrids S. hirsuta L., S. umbrosa L., S. spathularis Brot. and their hybrids can usually be distinguished by the relative shape, pubescence toothing, and width of the cartilaginous margin of the leaf-lamina (given in brackets) of the rosette leaves.

Author

R. J. Gornall, February 1988.

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Plant Crib

SCHOENOPLECTUS LACUSTRIS / S. TABERNAEMONTANI The size and colour characters can help to pick out S. lacustris and S. tabernaemontani from each other when they are growing together in the field, or to indicate plants to be examined more closely. The characters are not diagnostic, and the plants should be checked using the inflorescence characters (see also Stace’s New Flora). Intermediates have been recorded (Easy 1990), but it is unclear if these are hybrids or due to variable species. Some authors regard these as subspecies. Lousley (1933) provides a detailed review of the genus. S. lacustris (L.) Palla: Generally green and tall, but may have slightly glaucous stems; glumes smooth (awn often papillose); stigmas usually 3; nut at least bluntly trigonous. S. tabernaemontani (C. C. Gmel.) Palla: Generally 30-60 cm shorter than S. lacustris and glaucous; glumes densely beset with small, dark-brown, bluntly-hooked papillae on back, especially near the midrib; stigmas usually 2; nut biconvex or plano-convex.

a

b

Fruits (a) S. lacustris, (b) S. tabernaemontani.

References Easy, G. M.(1990). Nature in Cambridgeshire 32: 58. Lousley, J. E. (1933). Journal of Botany 69: 151-163.

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Plant Crib

SERAPIAS This genus has an extensive range from the Azores and Portugal in the west, to the Caucasus in the east, from N Africa in the south, to N France, Austria and Switzerland. Essentially it is a Mediterranean genus, with six species recognised in Flora Europaea. Some authorities split these into nearly twenty species, a situation further complicated by ready interspecific hybridisation. In recent years three species have been found in the British Isles. S. parviflora flowered in Cornwall (V.c. 2) in 1989-1991; it has been recorded in France north to Brittany. S. lingua was recorded in Guernsey in 1992, and also occurs north to Brittany. S. cordigera was recorded in Kent (V.c. 15) in 1996 and flowered again in 1997; it occurs in France north to Finistère. S. vomeracea is known from Switzerland but has not yet been recorded in the British Isles, although this is possible since it has a distribution pattern similar to the other species. There is also a 1918 record of S. neglecta from a cornfield on the Isle of Wight (BEC Rep. 5: 308); this is a localised species of the central Mediterranean and in this case seed may have been accidentally imported with cereal grain. There is no evidence available to date to suggest that S. cordigera, S. lingua and S. parviflora are not native, but their acceptance as such by Rich (1997) should be treated with caution. For a positive identification to be made, it may be necessary to dissect a flower, so that the key structures can be seen. The shape of the labellum is the best guide to identification, with particular reference to the relative proportions of the hypochile and epichile, the size and shape of the lateral lobes of the hypochile, the presence of hairs on the labellum, and the shape of the callus or calli (small protuberances at the base of the hypochile). 1

Epichile broad, as wide or wider than the hypochile; labellum rich reddish-brown, centre of both hypochile and epichile densely hairy; edges of epichile slightly wavy; two divergent calli at base of hypochile; epichile tends to hang vertically

1

Epichile narrower than hypochile, as long or longer, narrowed at the junction with the hypochile

2

Hypochile with a single dark purplish-brown callus at its base; lateral lobes of hypochile rather square in outline, darkly coloured, wider than epichile; epichile slightly longer, pointed, projecting almost horizontally S. lingua L. Hypochile bearing two parallel calli 3

2

S. cordigera L. 2

3

Flowers numerous, rather small and hidden by bracts; labellum often reflexed, epichile scarcely longer than hypochile; lateral lobes of hypochile rounded, projecting slightly downwards, not darkly coloured; epichile small, much narrower than hypochile, pointed, may bear a few hairs at base

3

Flowers large, well spaced, epichile at least twice the length of hypochile; lateral lobes of hypochile projecting well down, forming a sulcus on either side of the epichile, margins dark coloured, often maroon; epichile very long, blade-like (vomeracea means ‘like a ploughshare’), narrower than hypochile, usually pointing vertically downwards; centre of epichile may be hairy

S. parviflora Parl.

S. vomeracea (Burm.) Briq.

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Plant Crib

Serapias cordigera

Serapias vomeracea

Dissected flowers of Serapias. References Alibertis, C. & Alibertis, A. (1989). The Wild Orchids of Crete. C. & A. Alibertis, Crete. Baumann, H. & Künkele, S. (1982). Die wild-wachsenden Orchidéen Europas. Kosmos, Stuttgart. Cobbing, P. (1989). BSBI News 52:11-12. Davies, P., Davies, J. & Huxley, A. (1983). Wild Orchids of Britain and Europe. Chatto & Windus, London. Delforge, P. (1995). Orchids of Britain and Europe. Harper / Collins, London. Duperrex, A. (1961). Orchids of Europe. Blandford Press, London. Madge, S. (1994). Botanical Cornwall 6: 51-52. Rich, T. C. G. (1997). British Wildlife 9(2): 124-125. Author

D. C. Lang, November 1997. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib

SORBUS 1. General Warburg’s (1962) account of the British species is the major source of reference, with the following four exceptions: i) The S. latifolia group, which has been monographed by Sell (1989). ii) S. × thuringiaca (Ilse) Fritsch and S. × pinnatifida auct. (S. hybrida auct., non L.), which are widely confused. The latter is probably much the commoner taxon, distinguished by the distant pair of leaflets at the base of the leaf (Richards 1975). iii) The S. porrigentiformis group which has been investigated by Proctor & Groenhof (1992). iv) S. domestica; see Hampton & Kay (1995) and below. The most important characters for identification are leaves and fruits; the best time to identify Sorbus is thus in the autumn, though with experience they can be identified any time once the leaves are mature (young leaves tend to be thinner and light green). Flower characters may also be useful but have not been fully investigated. It is important to select the correct leaves on a plant: i) Examine two or three of the broadest leaves from the whorls on the short, lateral shoots if possible (ignore the narrowest leaves); descriptions refer to these unless otherwise stated. Leaves from the leading shoots are more variable. Leaves on inflorescence shoots, often collected with the flowers, are more variable. Sucker shoots from the base of the stem are often quite different to all other leaves. ii) Examine leaves from sunny positions on the outside or top of the canopy if possible. Shade leaves are often easier to reach but are more variable (e.g. shaded S. intermedia leaves may have free lobes at their base).

Branch of Sorbus showing short, lateral shoots

When pressing leaves, leave them attached to the short lateral shoots and turn at least one over to show tomentum on the back (sometimes easiest when the plants have wilted in the press for a few hours; leaves wilted out of the press tend to shrivel and distort). Leaf length:width ratios exclude the petioles. The shape, size and coloration of ripe fruits, and the distribution of lenticels (small, white scabs on the fruit surface) also provide important characters. When examining fruits, select the largest fruits (there are often two sizes present) and note length and width, and the distribution of lenticels before pressing. Estimating length:width ratios by eye can be surprisingly inaccurate. Colour is difficult to describe consistently, and it may be best to use RHS colour charts. When counting veins, count the total number of veins on a leaf and divide by two. Average at least five and round to nearest whole number.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Geographic lists This “key” lists, under very general groupings, the taxa found in various regions. This may be useful as a short cut to identification, but be aware that some taxa may be more widespread than current knowledge suggests. There are local accounts of Sorbus for Arran (Bignall 1980), Lancashire/Cumbria (Halliday 1997; Rich & Baecker 1986, 1992) and Torbay (Proctor & Proctor 1990); further local accounts would be invaluable. Frequent, widespread or common species are underlined, rare or very localised taxa in italics. 1a. Leaves simple (margins toothed), hairy below South-east England: S. aria, S. croceocarpa. South-west England: S. croceocarpa, S. porrigentiformis, S. aria, S. rupicola, S. vexans, S. wilmottiana, ‘Taxon D’. Northern England: S. aria, S. rupicola, S. lancastriensis, S. croceocarpa. Ireland: S. aria, S. rupicola, S. hibernica. Scotland: S. aria, S. rupicola, S. croceocarpa. Wales: S. aria, S. croceocarpa, S. porrigentiformis, S. rupicola, S. eminens, S. leptophylla. 1b. Leaves lobed (margins toothed), hairy below Eastern England: S. aria, S. intermedia, S. croceocarpa, S. latifolia s.s., S. decipiens. South-west England: S. aria, S. intermedia, S. devoniensis, S. croceocarpa, S. latifolia s.s., S. anglica, S. subcuneata, S. bristoliensis, S. vagensis, S. decipiens. Northern England: S. aria, S. intermedia, S. croceocarpa, S. devoniensis, S. latifolia s.s., S. devoniensis. Ireland: S. aria, S. intermedia, S. anglica, S. devoniensis. Scotland: S. aria, S. intermedia, S. arranensis, S. croceocarpa, S. decipiens. Wales: S. aria, S. intermedia, S. anglica, S. vagensis, S. leyana, S. minima, S. croceocarpa, S. latifolia. 1c. Leaves lobed or pinnate, ± glabrous England and Wales: S. aucuparia, S. torminalis, S. domestica. Ireland and Scotland: S. aucuparia. Key to groupings In the following accounts, the taxa have been grouped according to the following artificial key and the group numbers refer to the numbers of the accounts for ease of reference. 2 3

1 1

Leav es with at least one f ree lobe/leaflet at base Leav es lobed to simple, without any lobes/leaf lets f ree at base

2 2

Leav es regularly pinnate with 4 or more pairs of leaf lets Group Leav es with 1-2 free lobes/leaflets at base

3 3

Leav es simple (margins toothed) Leav es lobed

4 4

Leav es glabrescent; v eins 4-6 pairs; ripe f ruits brown S. torminalis (L.) Leav es hairy, at least below, v eins 7-14 pairs; ripe f ruits y ellow, orange, red or brownish

5

Leav es broad, grey -f elted below, lobes usually acute, shallow, v eins 7-13 pairs; ripe f ruits y ellow, orange or brownish

5

Leav es narrow, grey tomentose beneath, lobes rounded to acute, shallow to deep, v eins 7-10 pairs; ripe f ruits red

5

Leav es white beneath, lobes rounded, shallow, veins 8-14 pairs; ripe fruits redGroup

2. S. aucuparia / S. domestica Group 3 Group 6. S. aria aggregate 4 Crantz 5

Group 4. S. latifolia agg. Group 5. S. anglica/intermedia agg. 6. S. aria agg.

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Plant Crib 2. Sorbus domestica / S. aucuparia The recent discovery of S. domestica in two sites in S Wales (Hampton & Kay 1995; Hampton 1996) and three in Gloucestershire suggests that there could be other sites in the south and west or even possibly Ireland. All known populations occur on sea or estuarine cliffs where characters visible from a distance or through binoculars are valuable. Further, the irregular flowering and very rare mature fruiting of S. domestica increases the importance of vegetative characters. Plants should be looked for on south-facing limestone or rocky cliffs and slopes (S. aucuparia is uncommon in these situations), usually in semishade and associated with ancient woodland. All characters in the Table on the following page are for the apparently native plants, utilising unshaded, mature material unless otherwise stated. Leaves should be sampled as above, using the third leaf up a sterile short-shoot with five or more leaves, in full sun, as leaflet morphology, particularly degree of serration, varies along the shoot and with shade.

Branch morphology of (a) Sorbus domestica, (b) S. aucuparia

Stipules (c ) Sorbus domestica, (d) S. aucuparia

Ovaries and fruits (e) Sorbus domestica, (f) S. aucuparia Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Sorbus domestica L.

Sorbus aucuparia L.

Habit

Small tree (up to 20 m+ in cultivation) usually on soils of pH above 7

Small tree usually on soils of pH less than 6.5

Bark

On trunk and lower branches deeply and narrowly fissured, sharply flaking

On trunk and branches smooth, greyish, sometimes with vertical fissures at base in aged trees

Mature f lowering branches

Mostly on short shoots, not or rarely retaining main inflorescence peduncle through winter; fertile short shoots not thickened below, frequently wholly abscissed; branches which flower repeatedly of constant diameter (Fig. a)

Mature flowering branches usually showing some alternate long shoot growth; main inflorescence peduncle retained in winter; base of fertile short shoots thickened, often forming ‘ chains’ of sympodially linked fertile shoots (Fig. b)

Long shoots

Arising at mean angle of c. 60°, spreading; only central leaders, epicormic shoots and suckers ascending

Arising at mean angle of c. 30-40°, usually ascending and upswept

Buds

Ovoid, glabrous and viscid, shining, green orpale brown, scales 4-9; fertile buds opening before sterile buds

Conical on smooth stems, tomentose, especially on scale margins, dark brown or purplish, scales 2-5; fertile and sterile buds opening simultaneously

Y oung leav es

Emerging sterile shoot leaves silvery tomentose, visible from a distance especially in sun

Emerging leaves pastel green; hairy

Stipules

6-14 mm, initially simple, strap-like, viscid,soon divided at or below half-way (Fig. c), usually dropping early, but some can usually be found, especially on epicormic or basal shoots, and then larger and further divided

Initially lanceolate, later fan-shaped (Fig. d), persistent on long shoots

Leav es

Leaves often pale green or yellowed, finely pubescent above, with arachnoid hairs below; rachis green; leaflets 9-17; clusters of longer arachnoid hairs mixed with glandular papillae which occur along the rachis between leaflet pairs are frequently divided into 2 clumps; leaflets entire along ± first half of margin, the teeth usually closer together nearer tip; narrowing into outwardly curved acuminate apices (Fig. g); epidermal cells around stomata on lower leaf epidermis with central papillae flanked by radiating ridges, so that 5-6 papillae surround each stoma; no conspicuous ‘ collar’ ridgepresent around stoma

Leaves usually mid to dark green, often redtinged, glabrous above; rachis often red or redtinged at least above; leaflets 9-15; clusters of hairs and glandular papillae forming a single cluster or fringe between the leaflets; leaflets entire along first quarter of margin, teeth equally spaced and without acuminate apices (Fig. h); epidermal cells around stomata on lower leaf epidermis with sinuous median ridges but lacking papillae; stoma with ‘ collar’ ridge

Inf lorescence

A lax corymbose panicle up to 120 mm across with 40-80 flowers; inflorescence enlarging before leaves, but subtended by expanding leaves at flowering

A flat-topped dichasially cymose panicle up to 100 mm across with 50-400 flowers; inflorescence enlarging with leaves

Flowers

15-18 mm wide; corolla urcoleate, ovate, frequently reddish below; styles 5(-7)

6-10 mm wide, corolla narrowly urceolate; styles 3-4

Fruits and ov aries

Ovaries pyriform at anthesis, narrowing into pedicel (Fig. e); mature fruit rare, 18-25 mm wide, ovoid or pyriform, green, with few lenticels (in wild plants), often red on sunny side

Ovaries globose or ovoid at anthesis, not narrowing into pedicel (Fig. f); mature fruit 6-9 mm wide, globose, bright red, freely produced

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Plant Crib

Leaflets (g) Sorbus domestica, (h) S. aucuparia

Author

M . Hampton, January 1998.

Group 3. Sorbus, taxa with leaves with 1-2 free lobes at base of leaf

Group 3. Sorbus species with at least one free lobe at base (not to scale)

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib S. × pinnatifida auct. (? S. intermedia × S. aucuparia): Leaves ± lanceolate, length (1.5-)1.8-2.3(-2.4) times width; lowest pair of leaflets usually distant; veins 9-13 pairs. Often planted, rarely naturalised. S. × thuringiaca (Ilse) Fritsch: Leaves ± elliptic, length (1.5-)1.6-2.2(-2.4) times width; veins (including free leaflets) (9-)10-12(-13) pairs. Probably rare in wild and gardens. S. pseudofennica E. F. Warb.: Leaves ± ovate, length (1.3-)1.5-1.7(-2.2) times width; veins 7-9(-10) pairs. Arran (V.c. 100) only. S. intermedia (shade leaves): Leaves ± elliptic, length (1.5-)1.6-1.8(-1.9) times width; veins 7-9 pairs. Widely planted and naturalised. S. hybrida L.: Leaves ± ovate, length (1.2-)1.4-1.7(-1.9) times width; veins 8-10 pairs. Rare escape. S. leyana (shade leaves only): Leaves ± ovate, length 1.4-1.7(-1.9) times width; veins 5-7 pairs. Brecon (V.c. 42) only. Group 4. Sorbus latifolia aggregate Key to S. latifolia agg. with leaves and fruits 1 1

Ripe f ruits y ellow to orange Ripe f ruit brown to brownish orange

2 5

2 2

Leav es narrowly to broadly cuneate or narrowly rounded at base Leav es truncate, broadly rounded to rounded at base (sometimes some leaves broadly cuneate)

3 4

3 3

Veins (7-)8-9(-10) pairs Veins 10-13 pairs

S. bristoliensis S. decipiens

4 4

Leaf length 1.2-1.6(-1.8) times width Leaf length 1.1-1.3 times width

S. croceocarpa S. latifolia

5 5

Leaf bases cuneate to narrowly rounded Leaf bases truncate, broadly rounded or rounded

S. subcuneata 6

6 6

Ripe f ruit 10-15 mm, lenticels numerous Ripe f ruit 7-12 mm, lenticels f ew

S. devoniensis S. vagensis

Key to S. latifolia agg. based on leaves alone 2 4

1 1

Leav es narrowly to broadly cuneate or narrowly rounded at base Leav es truncate, broadly rounded to rounded at base (sometimes some leaves broadly cuneate)

2 2

Leav es obovate Leav es ovate to elliptical

3 3

Veins 10-13 pairs Veins (6-)8-9(-10) pairs

4 4

Leaf length 1.1-1.3 times width Leaf length 1.2-1.7(-2.1) times width

S. latifolia 5

5 5

Leav es simple or shallowly lobed Leav es lobed up to ¼ way to midrib

S. croceocarpa 6

6 6

Leaf base rounded Leaf base broadly cuneate

S. devoniensis S. vagensis

S. bristoliensis 3 S. decipiens S. subcuneata

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Plant Crib

S. bristoliensis

S. decipiens

S. croceocarpa

S. vagensis

S. latifolia

S. subcuneata

S. devoniensis

Group 4. Sorbus latifolia aggregate

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Plant Crib Group 4. S. latifolia descriptions (after Sell 1989) S. bristoliensis Wilmott: Leaves ± obovate, length 1.4-1.7(-2) times width, shallowly lobed mainly above middle up to 1/6 way to midrib; base broadly cuneate; veins (7-)8-9(-10) pairs. Largest ripe fruits 9-11 mm, longer than broad; yellow or orange; lenticels frequent, small to moderate, mainly at fruit base. Avon Gorge (V.c. 6, 34) only. S. croceocarpa P. D. Sell: Leaves mostly ovate, sometimes elliptic, rarely obovate, length 1.2-1.6(-1.8) times width, ± simple to shallowly lobed; base broadly rounded, sometimes broadly cuneate; veins 911 pairs. Ripe fruits 11-22 × 11-16 mm, subglobose; yellowish orange or deep orange; lenticels numerous, mostly small to medium with a few larger ones at the base. Widespread (V.c. 6, 11, 17, 20, 29, 32-34, 40, 44, 46, 49, 51, 52, 58, 60, 64, 69, 70, 80, 96, 99, 103). S. decipiens (Bechst.) Irmisch: Leaves elliptical or ovate, length 1.3-1.8(-2.5) times width, lobed up to 1/5 way to midrib; base rounded to cuneate; veins 10-13 pairs. Ripe fruit 8-17 × 8-16 mm, ellipsoid to sub-rotund; orange; lenticels scattered, medium to large. Rare (V.c. 6, 17, 105). S. devoniensis E. F. Warb: Leaves ovate to oblong-ovate, length 1.3-1.6(-1.8) times width, shallowly lobed up to ¼ way to midrib (usually less); base rounded; veins 7-9 pairs. Ripe fruits 10-15 × 11-15 mm, subglobose or wider than long; brownish-orange to brown; lenticels numerous, large at base becoming smaller above. W Britain and E Ireland (V.c. 2-4, 71, H6, H11-H13, H38). S. latifolia (Lam.) Pers.: Leaves broadly ovate, length 1.1-1.3 times width, shallowly lobed up to ¼ way to midrib; base broadly rounded, sometimes broadly cuneate; veins 7-9 pairs. Ripe fruit 14-17 × 15-17 mm; subglobose or slightly longer than broad; yellowish orange to deep orange; lenticels few to numerous, mostly rather large. Widespread (V.c. 6, 10, 17, 22, 23, 29, 33, 34, 46, 60-63, 83, 86, 96, 97, 106). S. subcuneata Wilmott: Leaves narrowly ovate or elliptic, length (1.5-)1.6-1.9(-2.5) times width; base cuneate to narrowly rounded; veins (6-)8-9(-10) pairs. Ripe fruits 10-13 mm, subglobose; brownishorange to orange; lenticels numerous, large below, smaller above. Rare (V.c. 4, 5). S. vagensis Wilmott: Leaves ovate to elliptical or rhombic-elliptic, length (1.1-)1.2-1.7(-2.1) times width, lobed from 1/7 to over ¼ of the way to the midrib; base cuneate or rounded; veins (6-)7-10 (-12) pairs; margin finely serrate with small teeth. Ripe fruit 7-12 mm, longer than broad or subglobose; brownish orange to brown; lenticels few, small to moderate. Rare (V.c. 6, 34-36). Group 5. Sorbus anglica / S. intermedia aggregate 2 3

1 1

Deepest lobes extending more than 1/3 way to midrib (measure along direction of veins) Deepest lobes extending less than 1/3 way to midrib (rarely a f ew to ½ way )

2

Leav es 6-9 cm, length 1.5-2.1(-2.6) times width, deepest lobes extending (1/3-)1/2-3/4 way to midrib; fruits 8-10 mm, ovoid. Arran (V.c. 100) only S. arranensis Hedl. Leav es 7-9 cm, length 1.4-1.7(-1.9) times width, deepest lobes extending (1/4-)1/3-3/4 way to midrib; f ruits c. 10 mm, subglobose. Brecon (V.c. 42) only S. leyana Wilmott Leav es 7-12 cm, length (1.5-)1.6-1.8 (-1.9) times width, lobed (1/4-)1/3-1/2 way to midrib; f ruits 12-15 mm, much longer than broad. Widespread S. intermedia (Ehrh.) Pers.

2 2

3 3

Leav es 6-8 cm, length (1.4-)1.8-2.2 times width, lobed 1/5-1/3(-1/2) way to midrib; f ruits 6-9 mm, subglobose. Brecon (V.c. 42) only S. minima (Ley) Hedl. Leav es 7-11 cm, length 1.3-1.7(-1.8) times width, lobed 1/6-1/4 way to midrib; f ruits 7-12 mm, subglobose. Variable between populations (see notes 1 and 2). Widespread but rare S. anglica Hedl. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 3

Leav es 7-12 cm, length (1.5-)1.6-1.8(-1.9) times width, lobed (1/4-)1/3-1/2 way to midrib; f ruits 12-15 mm, much longer than broad. Widespread S. intermedia (Ehrh.) Pers.

Notes 1. Sorbus anglica populations often have consistently different fruit and leaf shapes. The Irish plants and material from North Wales both differ from those in S Wales and SW England and both may merit recognition as distinct taxa. Some leaves may be nearly simple. S. anglica often comes into leaf and flowers before other species. 2. Sorbus anglica and S. intermedia are the two commonest species, and might be confused. Leaves of S. anglica are usually obovate and cuneate at the base, and the fruits are subglobose or broader than long. Leaves of S. intermedia are usually elliptic and mostly broadly rounded to truncate at the base, and the fruits are much longer than broad.

Group 5. Sorbus anglica/intermedia aggregate Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 6. Sorbus aria aggregate This group contains the very variable S. aria, and the mainly endemic apomictic species which are usually very constant within populations, and very a little between populations. M any other taxa are planted in gardens, towns and cities, and will no doubt become naturalised with time. Key to S. aria agg. with leaves and fruits (see also Warburg 1962) 1 1

Fruits longer than broad Fruits subglobose or broader than long

2 5

2 2

Veins usually more than 10 pairs Veins 8-9(-10) pairs

3 4

3 3 3

Teeth markedly biserrate, prominent; leaves obov ate, mainly 9-12 cm Teeth uniserrate to biserrate; leav es very v ariable Teeth uniserrate, leaves 15+ cm

4 4

Fruits 12-15 mm long Fruits 8-12 mm long

5 5

Veins usually more than 10 pairs Veins 8-9(-10) pairs

6 6

Lenticels numerous Lenticels f ew, large, at base of f ruit

7 7

Leav es obovate, sometimes almost round Leav es ovate

8 8

Leaf length 1.6-2.5 times width Leaf length 1.3-1.7 times width

9 9

Teeth strongly biserrate Teeth unequally uniserrate

S. leptophylla S. aria S. vestita S. vexans S. wilmottiana 6 8 S. aria 7 S. eminens S. hibernica S. rupicola 9 S. porrigentiformis S. lancastriensis

S. aria aggregate descriptions (mainly after Warburg 1962) S. aria (L.) Crantz.: Leaves ovate, elliptic or sub-rhombic (rarely orbicular or obovate), length 1.1-1.6 (2.5) times width, base cordate to rounded, veins (9-)10-14(-15) pairs, sometime shallowly lobed, teeth uniserrate to biserrate. Ripe fruits ?8-15 mm, usually longer than broad (rarely a little broader than long), lenticels usually numerous, small, scattered over most of fruit. Widespread throughout Britain and Ireland. S. aria is very variable. Adjacent specimens can often look so different that they may be thought to be different species. Any plant not agreeing with the other species in this group probably belongs here. Salmon (1930) gives notes on the varieties of S. aria s.s., though it is unlikely that most merit recognition, with the possible exception of var. longifolia Pers., which has very narrow leaves; this variety thus is sometimes mistaken for S. rupicola although it is very different in all other characters. S. aria-like plants in Galway, W. Ireland with very small leaves and few veins are similar to plants in the Pyrenees (?var. obtusifolia), and may be a distinct taxon (further investigation required). Small leaved plants also occur in the Avon Gorge. S. vestita Wall. (S. cuspidata): Leaves elliptic to obovate, large 15-20 cm, often cuspidate at apex, sparsely toothed. A garden plant from the Himalayas, possibly sometimes naturalising.

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Plant Crib

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Plant Crib

Group 6. Sorbus aria aggregate

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Plant Crib S. eminens E. F. Warb.: Leaves ovate-orbicular, obovate-orbicular or sub-rhombic, length 1.1-1.4(-1.7) times width, base broadly cuneate or curving outwards, veins (9-)10-11(-12) pairs, teeth biserrate. Ripe fruits ?12-14.2 × ?13.4-16.5 mm, broader than long, lenticels moderate, small or large, over most of fruit. Rare (V.c. 6, 34, 35, 36). Differing slightly between sites. The leaves are often almost circular (like tennis ball in size and shape), and the leaf base often arches outwards. Proctor & Groenhof (1992) have pointed out the close relationship between S. eminens, S. hibernica and a population from the M enai Straits, N. Wales. S. hibernica E. F. Warb.: Leaves ovate to obovate, length (1.1-)1.2-1.5(-1.8) times width, base broadly cuneate or rounded, veins (9-)10-11(-12) pairs, teeth biserrate. Ripe fruits ?(9-)12-14 × ?(10-)13-15 mm, broader than long, lenticels moderate, few, mainly at base of fruit. Widespread but very local in Ireland. S. lancastriensis E. F. Warb.: Leaves obovate, length (1.3-)1.4-1.75(-1.9) times width, base cuneate, veins (6.5-)8-10(-11) pairs, teeth unequally serrate. Ripe fruits ?11-12 × ?13-15 mm, broader than long, lenticels medium, over most of fruit. Rare (V.c. 69, 70; see Rich & Baecker 1986). S. leptophylla E. F. Warb.: Leaves obovate, length (1.3-)1.5-1.7(-1.9 or 2.5 on some shoots) times width, base cuneate, veins (9-)11-12(-13) pairs, teeth prominently biserrate. Ripe fruits ?c. 20 mm, longer than broad, lenticels large, few mainly at base of fruit. Rare (V.c. 42, probably also 47). Typically forming a shrub with pendulous branches sprawling against cliff faces, but plastic in habit and leaf size (often distinct when large). S. porrigentiformis E. F. Warb.: Leaves obovate, length 1.3-1.7 times width, base cuneate, veins (7-)810(-11) pairs, teeth strongly biserrate. Ripe fruits ?9-12.4 x ?11-13.8 mm, broader than long, lenticels medium, over most of fruit. Widespread in S Wales and SW England but very local (V.c. 3, 6, 34, 35, 36, 41, 42, 43, 44; plants on the M enai Straits, N Wales were ascribed to S. porrigentiformis by Warburg, but are almost certainly not that taxon). S. porrigentiformis has two distinct forms (Proctor & Groenhof 1992): (a) twiggy shrub with obovate leaves; fruits crimson, broad 9-10.8 x 11-13.8 mm; widespread in England and Wales. (b) oblong, biserrate leaves; fruits scarlet, subglobose, larger, 11-12.4 × 12-13.7 mm; S Wales. S. rupicola (Syme) Hedl.: Leaves elliptic to obovate-elliptic, length (1.4-)1.6-2.5 times width, base cuneate, veins (5-)6-9(-10) pairs, teeth usually uniserrate, often curving towards apex. Ripe fruits ?10.5-13 × ?11.7-15 mm, broader than long, lenticels medium, over most of fruit. Widespread. S. wilmottiana E. F. Warb.: Leaves elliptic to obovate-elliptic, length 1.6-2.0(-2.7) times width, base cuneate, veins 8-9(-10) pairs, teeth usually biserrate; fruits 10-13(-14) mm long × (9-)10-12(-13.5) mm wide, ± as long as or longer than broad, lenticels few, large, mostly at base of fruit. Rare (V.c. 6, 34). S. vexans E. F. Warb.: Leaves obovate, length (1.4-)1.5-1.9(-2) times width, base cuneate, veins (5-)6-9(10) pairs, teeth usually unequally biserrate. Ripe fruits ?12-15 mm, longer than broad, lenticels few, moderate, mainly at base of fruit. Rare (V.c. 4, 5). S. vexans includes two distinct forms which are best separated in fruit (leaf differences minor) (Proctor, Proctor & Groenhof 1989). (a) vexans s.s. (b) Taxon “D” with broader, deep red fruits. References Bignall, E. (1980). Glasgow Naturalist 20: 59-64. Halliday, G. (1997). A Flora of Cumbria. Lancaster. Hampton, M . (1996). BSBI News 73: 32-37. Hampton, M . & Kay, Q. O. N. (1995). Watsonia 20: 379-384. Proctor, M . C. F., Proctor, M . E. & Groenhof, A. C. (1989). New Phytologist 112: 569-575. Proctor, M . C. F. & Groenhof, A. C. (1992). Watsonia 19: 21-37. Proctor, M . E. & Proctor, M . C. F. (1990). Torquay Natural History Society: Transactions and Proceedings for the year 1988-1989. pp. 131-140. Rich, T. C. G. & Baecker, M . (1986). Watsonia 16: 83-85. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Rich, T. C. G. & Baecker, M . (1986). Watsonia 19: 138-14. Richards, A. J.(1975). Sorbus L. in Stace, C. A. ed., Hybridisation and the flora of the British Isles. London. Salmon, C. E. (1930). Journal of Botany 68: 172-177. Sell, P. D. (1989). Watsonia 17: 385-399. Warburg, E. F. (1962). Sorbus L. in Clapham, Tutin & Warburg, Flora of the British Isles. Cambridge University Press, Cambridge. Authors

T. C. G. Rich with contributions from many authors including L. Houston, M . A. R. & C. Kitchen, M . C. F. Proctor and P. D. Sell, 1991-1998.

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Plant Crib

SPARGANIUM 1. Collection notes Sparganium fruits usually fall as soon as they are ripe enough to show their proper characters and usually need packeting, and very careful timing in their collection. For a recent monograph, see Cook & Nicolls (1986, 1987). Sparganium is very difficult to identify from vegetative material, and the following key should be treated with care. All juvenile material has flat, light green leaves and much the same is found in totally submerged leaves. 2 3

1 1

Leaves flat Leaves triangular in section

2 2

Leaf base inflated Leaf base not inflated

3 3

Leaves smaller, light green, with the tips green up to about the last 1 mm Leaves darker green with distinct brown tips S. erectum L

S. angustifolium Michx. S. natans L. (S. minimum Wallr.) S. emersum Rehmann

S. × diversifolium Graebn. (S. angustifolium × S. emersum) may be found with one or both parents. Hybrids are intermediate between the parents in vegetative and floral characters - the Fl has the inflated leaf-bases of S. angustifolium (even when growing terrestrially) and the remote male heads of S. emersum. Stigma length and anther size are intermediate (Cook & Nicolls 1986). 2. Sparganium erectum Four subspecies of S. erectum L. have been recorded in the British Isles (Cook 1961). The taxa are consistent in mature fruit shape and size (intermediates are unknown) and differ in geographic range, but apparently not habitat. They are under-recorded because identification has to be made on ripe brown fruit, which does not mature until late in the season. They cannot be separated vegetatively. In the following key, length excludes the style and width is measured at the shoulder. 1 1

Fruit with distinct shoulder, upper part dark brown to blackish 2 Fruit with indistinct shoulder, spherical to ellipsoid, upper and lower parts a uniform shiny, light brown 3

2 2

Fruits (5-)6-8(-10) mm long, (3-)4-6(-7) mm wide; upper part of fruit flattened subsp. Fruits 6-7(-8) mm long, 2.5-4.5 mm wide; upper part of fruit domed, wrinkled below style

erectum

subsp. microcarpum 3 3

subsp. neglectum subsp. oocarpum

Fruit ellipsoid, 7-9 mm long, 2-3.5 mm wide Fruit ± spherical, 5-8 mm long, 4-7 mm wide

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib

a

b

c

d

Fruits of S. erectum (a) subsp. erectum, (b) subsp. microcarpum, (c) subsp. neglectum, (d) subsp. oocarpum. (del. R. V. Lansdown).

S. erectum L. subsp. erectum: Fruit cuneate-obpyramidal (5-)6-8(-10) mm long, (3-)4-6(-7) mm wide, with a distinct shoulder between upper and lower part; lower part pyramidal, (4-)5-7(-8) mm long, light brown in colour; upper part flattened, dark brown to black in colour, in cross-section sharply 3-5 angled. Style less than 2 mm long, persistent. Ovary usually bi-locular, but occasionally uni- to trilocular (Fig. a). England north to the Midlands, Isle of Man, Wales. S. erectum L. subsp. microcarpum (Neuman) Domin: Fruit obpyramidal with a rounded apex, 6-7(-8) mm long, 2.5-4.5 mm wide, with a distinct shoulder between the upper and lower parts; lower part pyramidical, 4-6 mm long, light brown with a slight constriction below the shoulder. The upper part domed with a longitudinal ridges below the style, dark brown in colour. Below the shoulder, fruit 3-5 angled in cross-section. Style persistent, less than 2 mm long. Ovary usually uni- rarely bi-locular (Fig. b). Widespread in England, Ireland, Scotland and Wales. S. erectum L. subsp. neglectum (Beeby) K. Richt.: Fruit ellipsoidal, 7-9 mm long, 2-3.5 mm wide, shoulder between upper and lower parts indistinct. Upper and lower parts conical, uniform light brown, shiny. Lower part 4-6 mm long. In cross-section fruit barely angled. Style persistent, usually more than 2 mm long. Ovary unilocular (Fig. c). Widespread in England, Ireland, Scotland and Wales. S. erectum L. subsp. oocarpum (Celak.) Domin: Fruit ovoid to spherical, 5-8 mm long, 4-7 mm wide, uniform light brown in colour, shoulder between upper and lower parts indistinct, upper part hemispherical, lower part broadly pyramidal, 2.5-5 mm long, almost circular in cross-section. Style persistent; usually less than 2 mm long. Ovary uni-, rarely bi-locular (Fig. d). England north to the Midlands, Wales. This subspecies shows poor fertility which may be due to hybrid origin (possibly subsp. erectum × subsp. neglectum). References Cook, C. D. K. (1961). Watsonia 5: 1-10. Cook, C. D. K. & Nicolls, M. S. (1986). Bot. Helvetica 96: 213-267. Cook, C. D. K. & Nicolls, M. S. (1987). Bot. Helvetica 97: 1-44. Author Based on pers. comm. with C. D. K. Cook, February 1988. Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Produced by M. D. B. Rich.

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Plant Crib

SPIRAEA, TAXA WITH ELONGATED TERMINAL PANICLE ONLY The following, still tentative, key covers naturalised taxa of the section Spiraea, in which the inflorescence consists of an elongated, terminal panicle (all taxa are keyed out in Stace’s New Flora; see also note 6 below). Species and hybrids of this section are sometimes used for hedging, especially on damp, peaty soils and hybrids of S. salicifolia may form extensive thickets. Other taxa tend to be less invasive, but are occasionally met in relatively wild situations. Leaf-shape is important in the identification of these plants, but must be judged from an adequate sample from the bush; a single, atypical shoot may be seriously misleading. Inflorescence-shape is also variable and should be judged from strong unshaded shoots. Flower-colour can be very helpful, and should always be noted before specimens are pressed and dried; some colours fade even in well-preserved material. The existence of a nectar-ring is sometimes important; if present, it forms a raised fleshy ring on the disc, inside the petals. The group as a whole is distributed throughout the northern hemisphere and numerous species have been introduced into cultivation. In the latter part of the last century, horticulturists, notably H. Zabel, carried out a comprehensive series of hybridisations, often between the most unlikely parents. Only a few of these hybrids have become widely cultivated, but odd bushes, particularly persisting in the vicinity of old estates, could easily present serious identification problems. M embers of the salicifolia group have frequently been crossed with members of other sections with lateral, umbel-like inflorescences; the resulting hybrids commonly have rather short, broadly conical, terminal inflorescences, and, very often, further heads borne on side shoots. One such cross, S. × brachybotrys, is included in the key, but others may occur as escapes. In view of the hybrid origin of most naturalised populations, pollen fertility is a useful character for reliable identification of these plants. Well-formed pollen stains with acetocarmine and can be recognised, with a little practise, with a low-power microscope. Infertile grains are mostly collapsed and colourless, though some may take up a little stain. Examination by high-powered microscopy, using Nomarski differential interference contrast, aids recognition of pollen contents, but unfortunately is not a technique likely to be available even to the few microscopists who may use this key. So far, only limited studies have been made, all on herbarium material, so the pollen percentage fertilities given in the key may be subject to modification. While, in most cases, there are easier ways to identify these plants, it currently appears that no identification of true S. salicifolia should be regarded as proven until its pollen has been checked. 1 1

Leav es glabrous, or at most, inconspicuously ciliate along margins of y oung leav es or at the base of main vein2 Leav es pubescent or tomentose beneath, at least on the v eins (lens!) 6

2

Inf lorescence open, conical in outline, with conspicuous, spreading or ascending lower side-branches; petals white or pale pink, rarely brighter; stamens about equalling petals; leav es elliptic, ov ate or lanceolate, f inely to v ery coarsely toothed or entire only near the base 3

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 2

Inf lorescence side-branches short and ascending to f orm a dense, narrowly conical to cy lindrical panicle; petals usually bright pink, rarely white; stamens equalling to twice as long as petals; leav es usually lanceolate, rarely ovate or oblong and then toothed mainly towards the apex 4

3

Petals (alway s?) white; leav es lanceolate or narrowly ov ate, more than 3 times as long as wide, f inely to coarsely toothed (Fig. e); inflorescence branches usually densely pubescent. (All records need reappraisal) S. alba Duroi var. alba Petals white or (rarely ) rose-pink; leav es broadly lanceolate, ov ate or elliptic, 2-3 times as long as wide, toothing usually coarse and sometimes compound (Fig. d); inf lorescence branches subglabrous to pubescent. (Occasionally naturalised)

3

S. alba Duroi var. latifolia (Aiton) Dippel [If petals rose- to bright-pink, inf lorescence rather dense and leav es broadly lanceolate, see also S. × rosalba = S. alba × S. salicifolia] 4

Leav es oblong to elliptic, with margins entire f rom base to at least mid-point, then f ew to sev eral large, obtuse to acute teeth; inf lorescence relativ ely long and cy lindrical; petals deep pink; nectar-ring absent. (At most a very rare escape, but all records require v erification)

4

Leav es narrowly to broadly lanceolate, regularly toothed from near base, nectar-ring distinct

5

Panicle cy lindrical to narrowly conical, its branches usually pubescent; petals usually bright pink; leav es narrowly lanceolate, ty pically with f ine, regular toothing almost f rom the base to apex (Fig. f ); pollen f ertility above 90%. (No authentic recent records) S. salicifolia L. Panicle cy lindrical to conical, its branches sub-glabrous or thinly pubescent; petals usually rose-pink; leaves rather broadly lanceolate, f inely to rather coarsely toothed (Figs. h-j); pollen f ertility below 20%. (Occasionally naturalised) S. × rosalba Dippel (S. alba × S. salicifolia)

5

S. douglasii Hook. subsp. menziesii (Hook.) Calder & Roy L. Taylor 5

6

Leav es of f lowering shoots 1.5-4 cm in length; terminal panicles broadly conical, scarcely longer than broad; lateral panicles usually present. (Leav es ov al or elliptic, those on f lowering shoots with 3-5 large, blunt, terminal teeth, dark and pubescent abov e, densely pubescent or grey -f elted beneath; inf lorescence grey ish-white f elted, petals pale pink). (Rare escape)

6

Leav es of f lowering shoots at least 5 cm in length; panicles all terminal, usually at least twice as long as wide7

7 7

Leav es felted beneath Leav es sparsely to densely pubescent beneath, but not felted

8

Leav es white- or grey ish-white f elted beneath, oblong or sometimes elliptic, margins entire to bey ond mid-point, then with f ew to sev eral large, obtuse to acute teeth (Fig. g); panicle cy lindrical, interrupted; petals 1.5-2 mm, deep pink; follicles of fruit glabrous, or sparsely ciliate along the sutures. (Occasional escape) S. douglasii Hook. subsp. douglasii Stem, inf lorescence and undersides of leav es y ellow- to y ellowish-white f elted; leav es narrowly elliptic to ovate, coarsely toothed except near base; inf lorescence narrowly to broadly conical, with regular spreading to ascending side-branches; petals 1-1.5 mm, white to deep pink; f ollicles densely pubescent. (Rare escape) S. tomentosa L.

S. × brachybotrys Lange (S. canescens × S. douglasii )

8

8 9

9

Leav es elliptic to oblong, margins entire to bey ond mid-point, then with f ew to sev eral large teeth towards apex; panicle interrupted-cy lindrical; petals deep pink; sepals def lexed in f ruit; nectar-ring absent; pollen f ertility high. (All records require v erif ication).

9

Leav es usually lanceolate, sometimes ov ate or elliptic, toothed f rom below mid-point; panicle cy lindrical to conical; petals usually pink; sepals def lexed to erect in f ruit; nectar-ring present though not alway s well dev eloped; pollen f ertility below 20%, often almost nil. (Frequent escapes) 10

S. douglasii Hook. subsp. menziesii (Hook.) Calder & Roy L. Taylor

10 Panicle cy lindrical or narrowly conical; leav es lanceolate, usually regularly toothed f rom near base (Fig. c)

pseudosalicifolia Silverside (S. douglasii × S. salicifolia; S. × billardii auct.)

S. ×

10 Panicle cy lindrical to conical; leav es lanceolate to elliptic-ov ate, of ten rather coarsely and irregularly toothed, base often cuneate and entire (Fig. a) (often cannot be readily separated f rom the preceding)S. × billardii Herincq (S. alba × S. douglasii)

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Spiraea leaves from flowering shoots. (a) S. × billardii, (b) S. × billardii var. macrothyrsa, (c ) S. × pseudosalicifolia, (d) S. alba var. latifolia, (e) S. alba var. alba, (f) S. salicifolia, (g) S. douglasii subsp. douglasii, (h) S. × rosalba nothovar. rosalba, (i, j) S. × rosalba nothovar. rubella.

NOTES

1. S. salicifolia and S. alba: - S. salicifolia is native through much of eastern Europe and Asia, but is replaced by S. alba in N America. The latter species was formerly included under S. salicifolia and this causes problems when interpreting old horticultural literature, particularly regarding the parentage of hybrids (see case of S. × billardii below). Following recent American authors, S. latifolia has been treated here as a variety of S. alba. The characters quoted in the key seem to give a workable separation of the two varieties, but on this basis, most or all recent determinations of var. alba should be referred to var. latifolia. There are very early records of ‘S. salicifolia’ as an escape in Britain, and these are likely to have been correct, but even if so, the species now appears to be extinct here. 2. S. alba × S. salicifolia: - Either variety of S. alba may be involved in this hybrid. That involving var. alba is S. × rosalba Dippel nothovar. rosalba, while that with var. latifolia is S. × rosalba nothovar. rubella (Dippel) Silverside (Figs. h-j). A few colonies in Wales and the Lake District have pale flowers and narrow, finely-toothed leaves and seem better referred to nothovar. rosalba, but most naturalised populations are nothovar. rubella. 3. S. douglasii × S. tomentosa (S. × fulvescens Dippel) has been reported as an escape, but those specimens seen have been S. douglasii.

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Plant Crib 4. S. alba × S. douglasii (S. × billardii Herincq): ‘Triumphans’ is a showy form with large, oval to elliptic, coarsely-toothed leaves and very large, solid panicles of bright pink flowers. Other populations seem to be var. macrothyrsa (Zabel) J. Duvign. with large, lanceolate leaves (Fig. b) and panicles often with conspicuous side-branches. The epithet ‘billardii’ has been consistently misapplied to S. douglasii × S. salicifolia due to the former use of S. salicifolia as an aggregate name. The epithet ‘menziesii’ has also been regularly misapplied to these two hybrids. 5. S. japonica L. f. differs from the above species in having flowers in pink, flat-topped corymbs. It is a variable plant, 1-1.5 m in height, with ovate to lanceolate, sharply toothed leaves. It can form thickets in old estate woodlands and is a rare escape. Several cultivars are grown under the name S. × bumalda Burv. 6. Other taxa occasionally recorded as escapes include S. canescens D. Don, S. media F. Schmidt, S. chamaedryfolia L. subsp. ulmifolia (Scop.) J. Duvign. and S. × vanhouttei (Briot) Carrière, plus the closely related invasive shrub, Holodiscus discolor (Pursh) M axim. None of these should be confused with the S. salicifolia group. References Jorgensen P. M . (1973). Blyttia 31: 29-33. Duvigneaud J. (1975). Natura Mosana 28: 33-55. Krussmann, G. (1986). Manual of cultivated broad-leaved trees & shrubs, vol. 3. Silverside, A. J. (1990). Watsonia 18: 147-181. Author

A. J. Silverside, February 1988, revised 1998.

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TRICHOMANES SPECIOSUM GAMETOPHYTES The report of the widespread distribution throughout the British Isles of the independent gametophyte plant of the Killarney fern, T. speciosum Willd., (Rumsey et al. 1990, 1998) has alerted botanists to search suitable habitats. To date gametophytes have been detected in Britain in 122 10-Km grid squares in 39 Vice-counties: 1, 2, 3, 4, 14, 34-36, 39, 41-49, 52, 57, 59, 62-64, 67, 69, 70, 88, 95, 98, 100-105 and 107-109. In Ireland, records from 22 10-km squares have been made in V.c. H1- 3, 6, 8, 10, 13, 16, 20, 26, 27, 33 and 35. Gametophytes are typically found growing in mats or hanging in loose tufts from dry rock surfaces in dark undercut areas at cliff bases, by stream-sides, in recesses amongst boulders in small natural caverns and in crevices. The majority of sites occur in woodland, those in open situations are predominantly coastal or rarely in hyper-oceanic montane areas. We believe that as more botanists become acquainted with the gametophyte, much of the appropriate country where the more acid (base-poor) sandstone, gritstones and the coarser volcanic rocks predominate will be shown to contain this stage of the Killarney fern. It should be noted, however, that although widespread, the gametophytic generation is by no means common. More than 75% of the grid squares mapped contain only single populations, in many cases restricted to a single micro-topographical feature. The morphology of the gametophyte has been described and illustrated (Rumsey et al. 1991, 1998) but is described again here with the hope that a wider audience will come to recognise it. It consists of filaments characteristically branched at rightangles, the individual cells of which are c.40-55 µm wide and 150-300 µm long, that grow interwoven into tufts or mats with an open, felt-like appearance. These are of a bright, almost fluorescent green when well hydrated, taking on a somewhat bluish-black metallic cast as the filaments crumple on drying. The gametophyte colonies can vary in overall size, from occurring as scattered filaments among bryophytes, to more or less pure patches covering several square metres to a depth of about one centimetre. The majority of sites, however, support small tufts ranging from thumbnail-sized patches to up to c. 10 cm2 . The combination of colour, shape and restriction to particular niches within habitats makes field recognition of the gametophyte relatively easy in the majority of cases. The filaments maintain a rigidity, giving a distinctive wool-like resilience, when lightly touched, and by which an experienced worker can identify the colony or mat. They are distinguished from bryophyte protonemata by their larger diameter filaments, the cells of which are without oblique end-walls, and from filamentous green and yellow-green algae by their pale brownish rhizoids and the presence of characteristically-shaped gemmifers, gemmae and gametangia (sex organs), when present. The most superficially similar algae grow in wet, wellilluminated positions or on very base-rich rock, where T. speciosum gametophytes have never been found. We must stress, at the time of writing, the species, in its entirety, is protected under laws in the European Union, the U.K. and the Republic of Ireland. We feel confident that the true picture of its distribution has yet to be determined. The characteristic structure of the filament mat is such that it can be confirmed in the field using a ×10 lens. New or potential sites should be reported to the appropriate Conservation Officer and details sent to F. J. Rumsey, Natural History Museum, Cromwell Road, London SW7 5BD.

References

Rumsey, F. J., Jermy, A. C. & Sheffield, E. (1998). Watsonia 22: 1-19. Rumsey, F. J., Sheffield, E. & Farrar, D. R. (1990). Pteridologist 2: 40-42.

Authors

F. J. Rumsey & A. C. Jermy, January 1998.

Filaments of mat of T.speciosum gametophyte.

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TRIFOLIUM

1. Vegetative identification of widespread Trifolium species The following key to widespread species of Trifolium (e.g. excluding species restricted to the Lizard and rarer casuals) may help with vegetative identification. The problem with the interesting, annual clovers is that by the time you get your eye in they are dying and setting seed. M ost seem to germinate in winter, so a vegetative key can help to extend the recording season. Of course you need to know you have an annual clover, or indeed that it is a clover, which may not be obvious at this stage. The drawings are all to the same scale, but there is considerable variation within most species. All have been drawn from live or herbarium specimens in BM, DOR and NMW. I have paid particular attention to the leaf and stipule shapes and the arrangement of the veins, parts not usually given much prominence in many illustrated floras. These important features are impossible to describe adequately; it is a matter of jizz. In the interest of clarity I have often only drawn one stipule and leaflet, and have not attempted to show hairs. 1 1 2

2 3

Perennial, creeping and rooting at nodes; glabrous Annual or perennial, but not rooting at nodes; glabrous or hairy

Leaf lets oblong; lateral v eins curv ed, neat, f requent and thickened at end; no crescent marking present (Fig. a)T.

fragiferum L. 2

Leaf lets obov ate; lateral v eins straight, not thickened at ends; white crescent marking present (see also T. occidentale below) (Fig. b) T. repens L.

3 3

Leaf lets ov ate to lanceolate, at least some more than 2.5 × as long as wide Leaf lets ov ate, obov ate, obcordate, less than 2 × as long as wide

4 4

Stipules hyaline, f an shaped, the veins ending in glandular teeth (Fig. c) T. strictum L. Stipules narrow with a long awn (long leav ed f orms of T. pratense hav e ov ate stipules with a short awn)5

5

4 8

Free part of stipules awl-shaped, shorter than the rest; terminal leaf let more than 7 mm wide, elliptical (Fig. d)T.

medium L. 5

Free part of stipules f iliform and longer than the rest; terminal leaflet less than 7 mm wide

6 6

Terminal leaf let less than 6 mm wide, longer than petiole, grey -green (Fig. e) Terminal leaf let as long as or shorter than the petiole, mid-green

7 7

Leaf lets 15-30 mm, elliptic to lanceolate, sometimes emarginate (Fig. f ) Leaf lets 10-20 mm, narrowly obov ate, often apiculate (Fig. g)

6

T. arvense L. 7

T. ochroleucon Huds. T. squamosum L.

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Trifolium, terminal leaflets and stipules Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 9 11

8 8

Large plants, annual or perennial; leaflets more than 10 mm Small annuals; leaflets usually less than 10 mm

9 9

Stipules ovate, obtuse, dentate; leaflets obcordate; annual (Fig. h) T. incarnatum L. Stipules ovate, entire; leaf lets ov ate to lanceolate; perennial (large forms of T. subterraneum may key out here but hav e entire stipules with an acute tip) 10

10 Stipules with long acuminate tip; leaf lets unmarked, glabrous (Fig. i) T. hybridum L. 10 Stipules with setaceous point or awn; leaf lets with white crescent, hairy at least below (Fig. j)

T. pratense L. 11 Leav es with long silky hairs on both sides (T. subterraneum can hav e sparse, stiff hairs) 11 Leav es glabrous or sparsely hairy

12 14

12 Veins on leaflets markedly thickened and recurved at ends (best seen when held up to light) (Fig. k)T. scabrum L. 12 Veins straight or slightly curv ed throughout, and not thickened at apex 13 13 Leaf lets obcordate; stipules ov ate, acute, v eins rarely prominent (Fig. l) T. subterraneum L. 13 Leaf lets obov ate, apiculate; stipules triangular, acuminate, hy aline, with dark red or green veins (Fig. m)T.

striatum L.

14 Leaf lets obov ate; stipules ov ate with long, acuminate tip (cf . T. ornithopodioides below) (Fig. n) 14 Leaf lets ± obcordate; stipules ovate, acute to shortly acuminate

T. glomeratum L. 15

15 Stipule apiculate, hy aline, with one v ein excurrent into awn; petiole usually more than twice as long as leaf let (Fig. o)

T. suffocatum L. 16

15 Stipule acute or acuminate, at least two veins; petiole usually less than twice as long as leaf let

T. micranthum Viv. 17

16 Terminal leaf let less than 5 mm, subsessile (Fig. p) 16 Terminal leaf let often larger, its petiolule at least 0.5 mm

17 Terminal leaf let more than 8 mm, its petiolule more than 5 mm; stipule acute (Fig. q)

T. campestre Schreb. 18

17 Terminal leaf let less than 8 mm (usually ), its petiolule less than 5 mm; stipule acuminate

18 Stipule with a long acumen; leaf let obcordate, serrate; petiole more than 2 × leaf let (Fig. r)

T. ornithopodioides L. 18 Stipule shortly acuminate; leaf let obov ate or orbicular, shallowly dentate; petiole usually less than 2 × leaf let (Fig. s)

T. dubium Sibth. Reference

Walls, R. M . (1994). Recording Dorset 4: 12-15.

Author

R. M . Walls, November 1997.

2. Trifolium occidentale / T. repens T. occidentale is known from an increasing number of localities in V.c. 1, 4, 41, 45, 52, H12, H20, H21 & S. It should be looked for near the sea in short, well-drained turf on cliff tops or on blown sand. It is distinguished from the widespread and variable T. repens as shown in the following Table (M ilton 1984; C. D. Preston, pers. comm. 1987). It also flowers earlier in the year.

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Plant Crib Trifolium occidentale D. E. Coombe

Trifolium repens L.

Leaflets

6-8(-10) mm, orbicular, markings usually absent; upper surface matt, slightly glaucous-green, crystalline; lower surface dark green, very glossy; lateral veins not translucent

10-25(-35) mm, ovate or obcordate, frequently marked with a white 'V'; the upper and lower sides similar in colour; lateral veins translucent in living plant

Petiole

With short, sparse, persistent hairs

Usually glabrous

Stipules

Deep vinous red

Green, sometimes with red veins, rarely vinous

Calyx

Becoming red above, upper 2 teeth often denticulate, parallel or convergent, broadly triangular

White with green veins, upper 2 teeth entire, divergent, narrowly triangular

Corolla

Creamy white, standard broadly elliptical, apex emarginate

White to deep red, standard oblong, apex rounded

References Coombe, D. E. (1961). Watsonia 5: 68-87. M ilton, J. N. B. (1984). BSBI News 37: 8-9.

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TRIGLOCHIN Triglochin maritima L. and T. palustre L. are difficult to separate when vegetative using characters given in Floras, although they are easily distinguished when in flower or fruit. The former is usually larger and stoloniferous, and with flattened tips to the leaves; the latter is smaller and non-stoloniferous, without flattened leaf-tips. All these characters are variable however, and those given by Rose (1981) have not proved helpful when naming grazed specimens. A consistent and reliable character however is ligule shape (Dalby 1988): relatively narrower and more pointed in T. maritima (Figs. a, b), and relatively shorter and blunter in T. palustre (Figs. c, d). Shape is much more important than size.

a

b

c

d

Ligule shapes in Triglochin (a, b) T. maritima, (c, d) T. palustre. References Dalby, D. H. (1988). Trans. Bot. Soc. Edinburgh 45: 127-129. Rose, F. (1981). The Wild Flower Key. F. Warne Ltd., London. Author

D. H. Dalby, M arch 1988.

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Plant Crib URTICA GALEOPSIFOLIA / U. DIOICA The status of narrow-leaved nettles at Wicken Fen has been studied by Geltman (1992); who referred them to the eastern and central European species, U. galeopsifolia. Narrow-leaved plants with few (or no?) stinging hairs occur scattered in damp habitats through England and Scotland (e.g. BSBI News 68: 10, 69: 31, 75: 48-49), and plants should thus be looked for elsewhere. The situation may however be considerably more complex (Friday 1997). U. galeopsifolia Wierzb. ex Opiz: Stinging hairs almost completely lacking, indumentum dense, of simple hairs; lowest flowering branches at nodes 13-22; flowering mid-July onwards; leaves usually long and narrow. U. dioica L.: Stinging hairs present; lowest flowering branches at nodes 7-14; flowering mid-June onwards; leaves variable, sometimes long and narrow.

Reference

Friday, L. (1997). Wicken fen. Cambridge. Geltman, D. V. (1992). Watsonia 19: 127-129.

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Plant Crib

VICIA M ature fruits are required for identification of many of the species in this genus, and should be collected for herbarium specimens. 1. Vicia sylvatica The prostrate, dwarf coastal var. condensata has been recorded in V.c. 4, 50, 70, 73, 74, 100, 101 and H39. It is distinguished from typical V. sylvatica L. as follows: Var. sylvatica: Stems 50-100 cm, weak, trailing or scrambling. Leaves 4-8 cm. Leaflets 12-20, more or less distant, 8-18 × 48 mm, ovate to ovate-oblong or elliptical, thin in texture. Tendrils 2-7 cm, 2- to 4- branched. Peduncles 5-18 cm. Raceme usually distinctly exceeding the leaves, lax, with 8-20 flowers. Corolla 15-20 mm. Open woods, scrub, rocky slopes, seacliffs. Var. condensata Druce: Stems 20-50 cm, somewhat rigid, procumbent to decumbent, forming compact patches and low hummocks. Leaves 2.5-5 cm. Leaflets 8-14, rather crowded, 6-10(-12) × 3-6 mm, ovate to suborbicular or broadly elliptical, slightly fleshy, often glaucous. Tendrils 1-4 cm, unbranched or 1- to 3-branched. Peduncles 2-5 cm. Raceme about as long as or only slightly exceeding leaves, compact, with 4-8(-12) flowers. Corolla 13-18 mm. Coastal shingle, sea-cliffs. Reference

Akeroyd, J. R. (1996). Watsonia 21: 71-78.

Author

J. R. Akeroyd, January 1998.

2. Vicia sepium The dwarf, prostrate coastal sand dune var. hartii is known from V.c.103, 108-109, H27 and H35. It can be distinguished from typical V. sepium L. as follows: Var. sepium: Stems 30-120 cm, ascending, climbing or trailing. Leaves 3-7 cm. Leaflets 8-18, 8-30(-40) × 4-12(-18) mm, ovate to ovate-oblong, subacute, obtuse or truncate. Tendrils 1-3 cm, 1- to 4-branched. Hedges, woodland margins and scrub; widespread in Europe. Var. hartii Akeroyd: Stems 5-20(-35) cm, procumbent, decumbent or weakly ascending, forming mats and low hummocks. Leaves 2-4 cm. Leaflets 6-14, 5-13 × 3-5 mm, ovate to elliptical or suborbicular, truncate to rounded. Tendrils 0.5-2 cm, usually unbranched or 1- to 2-branched, often absent or vestigial, sometimes replaced by a terminal leaflet. Sand-dunes. Reference

Akeroyd, J. R. (1996). Watsonia 21: 71-78.

Author

J. R. Akeroyd, January 1998.

3. Vicia sativa aggregate The taxonomy of this species aggregate has been much confused in the past, owing in part to former cultivated strains having escaped. The four British segregates, V. lathyroides, V. sativa subsp. nigra, subsp. segetalis and subsp. sativa differ by increasing size of most of their parts (and in that order). However, there is some overlap so that these characters are not alone sufficient for distinguishing the species. The leaflets on the lowest leaves of the flowering shoot are often markedly shorter Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib and broader than those on the upper leaves which bear flowers in their axils; plants with this character well-developed are termed heterophyllous.

Vicia sativa subspecies showing variation in leaves (a) subsp. nigra, (b) subsp. segetalis, (c ) subsp. sativa. Note subsp. nigra has much narrower upper leaves than the other taxa.

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Plant Crib V. lathyroides (V. sativa ) 2

1 1

Seeds tuberculate; flowers dull purple, 9 mm long or less Seeds smooth; flowers bright purple or bi-coloured, more than 9 mm long

2

Pods y ellow brown, constricted between seeds; flowers (11-)22-25(-30) mm, bi-coloured (rare)

2

Pods dark brown-black, not constricted between seeds; f lowers (9-)12-19(-26) concolorous or bicoloured

subsp. sativa

3 3

Plant markedly heterophyllous; flowers bright, concolorous Plant not, or scarcely heterophy llous; f lowers usually bi-coloured

3

subsp. nigra subsp. segetalis

V. lathyroides L.: Strongly heterophyllous; tendrils simple; flowers 6-9 mm, concolorous (usually dull purple); pods 18-30 mm, brown to black, smooth, glabrous; seeds tuberculate. The first taxa to flower. V. sativa L. subsp. nigra (L.) Ehrh.: Strongly heterophyllous (Fig. a); tendrils branched; flowers (9-)12-17(-19) mm, concolorous (usually bright purple); pods 23-28(-45) mm, brown to black, smooth or bristly; seeds smooth. V. sativa L. subsp. segetalis (Thuill.) Gaudin: More or less isophyllous (Fig. b); tendrils branched; flowers (9-)13-19(-26) mm, bi-coloured (with standard petal paler than the wings); pods 28-70 mm, brown to black, smooth, usually glabrous; seeds smooth. V. sativa L. subsp. sativa: More or less isophyllous (Fig. c); tendrils branched; flowers (11-)22-25(-30) mm, bi-coloured (with standard petal paler than the wings); pods (36-)50-80 mm, yellowish to brown, constricted between the seeds, often pilose; seeds smooth. References

Hollings, E. & Stace, C. A. (1978). Watsonia 12: 1-14. Killick, H. J. (1975). Watsonia 10: 288-289. Killick, H. J., Perry, A. R. & Woodell, S. R. J. (1998, in press). The Flora of Oxfordshire. Nature Conservation Bureau, Newbury.

Author

H. J. Killick, December 1997.

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VIOLA Species of Viola are, in the main, not difficult to identify, but careful examination of plants is often necessary. Specific pairs of taxa seem to consistently give problems.

1. Vegetative key to plants with floral axis present, but no open flowers 1 1

Plant with stipules lanceolate to ov ate-lanceolate, not leaf -like Plant with stipules leaf-like, pinnatif id, palmatifid, or at least deeply -lobed

2 7

2 2

Plant with leaves and pedicels all arising from the base (acaulous) Plant with leafy flowering stems

3 5

3 3

Plant with leafy, procumbent, rooting stolons; leaves and petioles hairy Plant without stolons; leaves and petioles glabrous or hairy

4

Plant with long, creeping rhizomes; leav es glabrous, orbicular-renif orm; petiole sometimes hairy

4

Plant without rhizomes; leaves hairy, triangular-ov ate to oblong-ovate; petiole hairy

5 5

Plant with a basal rosette of leav es (this dichotomy is likely to cause problems, but is usually clear on good material)6 Plant without a basal rosette of leav es; all leav es cauline, ov ate to ov ate-lanceolate

V. odorata 4

V. palustris V. hirta

V. canina, V. lactea and V. persicifolia 6 6

Leav es, petioles, and peduncles usually with f ine pubescence (× 20 lens), rarely glabrous (small plants may appear acaulous); leav es shov el-shaped V. rupestris Plant largely glabrous; leaves heart-shaped V. riviniana and V. reichenbachiana

7 7

Plant with long, slender, creeping rhizomes, producing solitary, unbranched f lowering stems V. lutea Plant without rhizomes (or v ery short and not creeping), producing usually much-branched f lowering stems 8

8 8

Mid-lobe of stipule usually lanceolate, ± entire, not leaf -like Mid-lobe of stipule usually ov ate-lanceolate or ov ate, crenate-serrate, leaf -like

V. tricolor V. arvensis

2. Viola odorata varieties The following key to varieties of V. odorata L. was prepared for Surrey but may be useful elsewhere. 1 1

Spurs v iolet-purple Spurs pinkish-purple

2 5

2 2

Petals bluish- or v iolet-purple Petals white (sometimes splashed with purple) or white suffused apricot

3 4

3

Petals bluish-purple; f lowering starting in spring; lateral petals bearded or not; summer leaves obtuse

3

Petals deep v iolet-purple; f lowering starting during winter; lateral petals bearded or not; plant and

var. odorata Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib f lowers often smaller, especially at onset of f lowering; summer leav es pointed

var. praecox Gregory

4

Petals white (sometimes splashed purple); lateral petals usually bearded

4

Petals white suf f used apricot, especially towards the base; lateral petals usually bearded

var. dumetorum (Jordan) Rouy & Foucaud var. sulfurea (Cariot) Rouy & Foucaud 5

Petals white (sometimes splashed pinkish-purple); lateral petals not bearded

5

Petals pinkish-purple throughout; lateral petals usually not bearded

var. imberbis (Leighton) Henslow var. subcarnea (Jordan) Partalore The status of many V. odorata records is often difficult to assess: var. praecox and var. sulfurea are often said to be likely introductions, but no doubt all the various colour forms are deliberately introduced from time to time. A clear indication of the nature of the individual locality is thus obviously of value with each record. Some ecological differences between variants have been reported, notably regarding var. imberbis and var. dumetorum, so it is also useful to indicate soil type with the record. There is also variation within some of these described varieties and it would be useful if recorders would indicate, for instance, whether white-flowered forms have pure white petals or petals with violet-purple or pinkish-purple splashing, or whether the lateral petals have tufts or hairs or not. Author

A. C. Leslie, 1988.

3. Viola odorata / V. hirta Although these two species are relatively distinct, the hybrid may occur with them on edges of scrub and grassland. The hybrid is unfortunately quite variable and it is not easy to tell from either parent due to back-crossing. The absence of stolons is diagnostic for V. hirta Leaves of V. odorata in the spring are shiny and ± glabrous. Leaves of both species may increase in size through the season, the appearance in late summer being very different from the spring. The difference in the hairs on the petioles is easily seen with a × 20 lens, though the measurements require a graduated lens (NB indumentum updated from Stace’s New Flora).

V. odorata L.

V. × permixta Jord.

V. hirta L.

Stolons

Present, plant sometimes forming extensive patches

Weak, short tends to form tight patches

Absent

Hairs on petioles

Very short (usually less than 0.25(-0.4) mm), deflexed to appressed

Intermediate

Longer (usually more than (0.25-)0.3 mm), patent to deflexed

Leaf shape

Broadly ovate to ovateorbicular, obtuse to rounded at apex, deeply cordate

Variable

Ovate, obtuse at apex, shallowly cordate

Stipules

Ovate to ovatelanceolate

Intermediate

Lanceolate to linearlanceolate

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Flowers

Scented or not scented, deep purple to pink white or blue

Weakly scented or not

Not scented; blueviolet, rarely white

Fertility

Fertile

Partially fertile

Fertile

4. Viola hirta / V. riviniana In tightly grazed grassland vegetative leaves of these two species can be surprisingly similar, though in most cases there should be no difficulty separating them. In flower or fruit (cleistogamous flowers tucked around the base of the plants may be present until quite late in the year) they are readily distinguished (V. hirta has blunt sepals, V. riviniana has acute sepals). V. hirta L.: Usually with abundant deflexed to patent hairs on petioles and leaflets (exceptionally glabrous); stipules pale, with or without weak, often glandular-tipped (Fig. a), lateral teeth; margins of stipules often hairy. V. riviniana Rchb.: Usually glabrous, sometimes with sparse pubescence on leaf surfaces; stipules dark, usually with strong, thread-like, spreading, non-glandular-tipped lateral teeth (exceptionally lower ones glandular-tipped) (Fig. b); margins of stipules glabrous.

a

b

Stipules. (a)V. hirta, (b) V. riviniana.

5. Viola rupestris / V. riviniana / V. hirta V. rupestris F.W. Schmidt is currently only known from limestone in northern England, but given its widespread occurrence on the continent could occur elsewhere in Britain and Ireland. Full details of all colonies of this Red Data Book species should be recorded. The Viola rupestris form from the ‘classic’ locality on Widdybank Fell, Teesdale (V.c. 66) is easily distinguished, but the much less distinctive form on the south-east slopes of Ingleborough (V.c. 64), though abundant, remained undiscovered until recent years and may still await discovery in other parts of the Dales. It is still often overlooked or confused, for several reasons. i) In most seasons it flowers very sparsely indeed, often less than 1% of plants flowering. ii) M ost plants are very small and insignificant. iii) British texts give as diagnostic for this species the presence of very short pubescence on stems, petioles and capsules. However, many colonies on Ingleborough consist of largely glabrous plants, and thus are likely to be passed over as V. riviniana. The existence of ± glabrous forms of V. rupestris in Britain (Roberts 1977) is still not widely appreciated, and for instance is not mentioned in Stace’s New Flora. Beware: V. riviniana may also have sparsely pubescent upper leaf surfaces (cf. below) and some forms can be densely hairy, though the hairs are longer than in V. rupestris and more reminiscent of those in V. hirta.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib In flower, look for a narrow band of darker violet separating the violet on the lower lip from the white in the throat. This is usually present in V. riviniana, and absent in V. rupestris. The background colour in V. rupestris is often paler than that in V. riviniana. The spur in V. riviniana is long, stout, and often vertically grooved at the end, and often with a little sharp projection from its upper-side near the tip. The spur on V. rupestris is shorter, conical to a rounder tip without groove or projection. The colour of the spur in both species varies. However, V. rupestris is perhaps most easily found in summer, when plants have finished flowering but are well-grown and more conspicuous. V. rupestris and V. riviniana (especially its dwarf variety var. minor (M urb. ex Greg.) Valentine) have an almost identical growth form with central non-flowering leafrosette and decumbent flowering/fruiting stems arising from below the rosette, although V. rupestris is more condensed. The form of the leaves is diagnostic in well-grown plants. The leaves of V. rupestris are shovel-shaped, blunt-tipped, with a slightly cordate or ± truncate base, whilst those of V. riviniana are pointed and heart-shaped, with a strongly cordate base. In V. rupestris the sides of the mature leaves are often curled upwards (making the leaf ‘scoop-shaped’), whereas in V. riviniana the basal lobes are often up-curled. V. rupestris plants are often deep green, grey-green, or tinged deep red (the latter can be virtually invisible); V. riviniana is a constant dull mid-green. Basal leaves of Campanula rotundifolia can also often catch the eye, being of a similar shape and colour (although paler), and occurring in the same habitat.

The hybrid between the two, V. × burnatii Gremli, has been recorded in Durham but has not yet been found elsewhere. It is generally intermediate between the parents in leaf and flower characters and the pubescence is even finer than in typical V. rupestris. No seed is set. It should form conspicuous vigorous spreading patches. Viola rupestris grows in a few distinctive habitats, for which one can soon develop an eye. On Ingleborough these are: - thin soils (clayey or peaty) in gravelly areas on the exposed summits of plateaux; - fine screes of pea-gravel where these are intermixed with clayey soil; - bare sides or tops of hummocks of gravelly calcareous boulder clay; - very rarely in Sesleria on the limestone bedrock itself. In all these places the main feature is the open and exposed character of the community, usually consisting only of sparse Sesleria, Festuca ovina and Carex flacca with much open ground. By contrast V. riviniana grows either in crevices between larger stones, in the richer soil in the grykes of pavements, or in dense Agrostis/Festuca turf. The two species never seem to occupy the same habitat in V.c. 64, although in other areas of the Dales, V. riviniana crops up in habitats similar to those occupied on Ingleborough by V. rupestris. In Teesdale, the colonies are in thin, open Festuca/Carex turf over the crumbly ‘sugar’ limestone outcrops, or in open areas of calcareous sand from the eroding limestone. Pubescent plants of V. rupestris may be confused with V. hirta, which does grow rarely in higher altitude limestone turf. V. hirta has longer - almost bristly - hairs, a longer and larger leaf with a ± pointed leafapex, and obviously blunt sepals; it mostly grows in closed turf. Both species may sometimes have white flowers. References

Roberts, F. J. (1977). Watsonia 11: 385-386. Valentine, D. H. & Harvey, M. J. (1961). Proc. BSBI 4: 129-135. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Author

F. J. Roberts, December 1997.

6. Viola riviniana / V. reichenbachiana / V. × bavarica The Table has been compiled from a number of sources including Valentine (1950), Stace (1975) and Stace’s New Flora.

V. riviniana Rchb.

V. × b avarica Schrank

V. reichenb achiana Jord. ex Boreau

Leaves

Obtuse to rounded at apex, thicker, changing very little in size through the season (Fig. a)

Intermediate

Obtuse to acuminate at apex, thinner, increasing in size in late season (Fig. b)

Adventitious buds on roots

Present or absent

Probably absent

Absent

Sepals

Appendages 1.5 mm or more and enlarging in fruit (Fig. f); those of non-cleistogamous flowers appressed (note 1) in fruit

Intermediate

Appendages 1.5 mm or less and remaining so in fruit (Fig. g); those of non-cleistogamous flowers divergent in fruit

Flowers

Slatey-blue, lower petals broader; purple veins branching out to fill the lower proximal part of the petal which is white at the base and violet distally (Fig. c)

Colour and shape intermediate, venation like V. riviniana (Fig. d)

Lilac, lower petals narrower; veins fewer in number and restricted to centre of petal (Fig. e)

Spurs

White to yellow or purplish, paler than petals, stout, usually notched or furrowed at apex

Colour intermediate but Lilac, darker than shape nearer V. petals, slender, riviniana sometimes weakly notched at apex

Fertility

Pollen and seeds highly fertile; c. 19 seeds per capsule, lighter brown, larger and heavier

Pollen and seeds low fertility, c. 1%; often high proportion of white or pale seeds in ripe, erect pods

Pollen and seeds highly fertile; c. 11 seeds per capsule, dark brown, smaller

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Note 1. Cleistogamous flowers have sepals appressed in fruit in both species. Sepals of cleistogamous similar and small in both species.

flowers may be

With practice it may be possible to separate V. riviniana and V. reichenbachiana vegetatively using differences between the leaves (Phillips 1982). The leaves differ in shape and proportions (more pointed in V. reichenbachiana) and texture (thinner and less opaque in V. reichenbachiana). Although somewhat difficult to define, the characters require careful comparisons are made but there is much variation in both species. As the season progresses the very large leaves of V. reichenbachiana show the differences even more clearly. Basal rosette leaves of both species tend to be broader and less pointed at the apex, and they may be slightly pubescent on the upper and sometimes lower surfaces (×10 lens). Some populations of V. riviniana are able to form clonal patches by adventitious buds on the roots; this character has not been reported in V. reichenbachiana. The best characters are however those of the flowers and fruit; V. riviniana has broader larger pale blue flowers with a pale spur and the sepals enlarge noticeably in fruit.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib In Europe and Britain, the two parents tend to be partially ecologically separated, V. riviniana in the open and V. reichenbachiana in calcareous woodland though there is considerable overlap in their ecological requirements. Where their habitats are fragmented they come into contact regularly, and this may have resulted in extensive hybridisation. V. reichenbachiana generally comes into flower a week or two before V. riviniana and finishes earlier which may help pick out good V. reichenbachiana in early spring, but there is much overlap.

Not only are the two species much confused by botanists, but the status of their hybrid seems unclear. There are two possible scenarios: i) hybrids are rare and V. riviniana is very variable, the position adopted by those with a broad species concept (cf. Valentine 1941). ii) hybrids are common and V. riviniana should be treated more strictly. Continental authors tend to regard ‘good’ V. riviniana as having yellow spurs and plants with broad purplish spurs as hybrids. These hybrids tend to be highly fertile, disagreeing with the experimental evidence from hybridisation of British plants (Valentine 1950). Hybrids are reported to be common and widespread in Britain and Ireland yet are rarely recorded. They tend to be vigorous, and are best determined in the field by comparing local populations. On the whole they resemble V. riviniana more closely on floral characters. Individual herbarium specimens tend to be more like V. riviniana and are difficult to determine. References

Phillips, E. N. M. (1982). BSBI News 31: 19. Stace, C. A. (1975). Hybridisation and the flora of the British Isles. AcademicPress, London. Valentine, D. H. (1941). New Phytologist 40: 189-209. Valentine, D. H. (1950). New Phytologist 49: 193-212.

7. Viola canina / V. riviniana / V. × intersita V. canina appears to be declining inland on heaths and now seems most common on sand dunes. It also occurs rarely in the uplands and in fens. Care should be taken distinguishing it from V. riviniana. It may be over-recorded for several reasons: i) Beginners who know of ‘dog-violets’ associate the name canina with the commonest violet which is V. riviniana. ii) Variation in spur colour from white to yellow to purple within populations of V. riviniana (cf. above) may make it appear that two species are present rather than one. iii) Historically V. riviniana was included in V. canina. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib The parents, once known, are easily distinguished. The hybrid between the two occurs rarely where the parents grow together - it forms vigorous ± sterile patches and is obviously intermediate.

Viola canina L.

V. × intersita Beck

V. riviniana Rchb.

Habit

Basal rosette absent, all leaves on stems

Basal rosette absent

Basal rosette present in addition to leaves on stems

Leaves

± Lanceolate, mostly shiny, strongly reticulate below, dark green, thick, glabrous (Fig. a)

Intermediate

Orbicular-ovate to ovate, shiny or dull, not strongly reticulate below, mid-green, thinner; sometimes sparsely hairy (Fig. b)

Stipules

Teeth triangular, strong, Intermediate pointing forwards (Fig. c)

Teeth slender, pointed sideways (Fig. d)

Flowers

Spur yellow, notched or Spur white to yellow not or pale purple

Spur white to yellow or pale purple

Fertility

Fertile

Fertile

± Sterile

Stipules (c ) V. canina

(d) V. riviniana.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib 8. Viola lactea / V. canina V. lactea is most closely related to V. canina, from which it can be distinguished as below (Moore 1957). A map of V. lactea is given in Scarce Plants.

V. lactea Sm.

V. canina L.

Habit

Subglabrous; stems ascending

Glabrous or sparingly pubescent; stems decumbent to erect

Leaves

Lanceolate to ovate-lanceolate c. 1.4-2.5 times as long as wide; apex subacute; base cuneate to truncate; margin shallowly crenate-serrate; foliage sometimes purplish

Ovate to ovate-lanceolate c. 1-1.5 times as long as wide; apex obtuse or subacute; base truncate or shallowly and widely cordate; margin crenate or crenate-serrate

Stipules

Large (except the lower), equalling or somewhat longer than the petiole, lanceolate to ovatelanceolate, coarsely and irregularly fimbriate-serrate or dentate

Rather small, about half as long as the petiole, ± lanceolate, distantly serrate-dentate, with few short and stout teeth

Corolla

Petals narrow (3-4 times as long as broad), creamy to pale lilac

Petals obovate (1.5-2 times as long as broad), blue with little or no violet tint

Flowering

M ay to June

April to June

Typical habitat

Heaths, especially near the sea

Downs, dunes and sandy heaths / grassland

Many early authorities (e.g. Gregory 1912) considered hybrids between these species to be frequent in Britain. However, despite the reasonable pollen-fertility of artificial F1 hybrids, which are morphologically intermediate between the parents, natural occurrences are rare. Only occasional massive habitat disturbance breaks down the strong edaphic factors separating the species. Floral features (Moore 1957) are the only sure morphological guides to recognition of the hybrids. References

Gregory, E. S. (1912). British Violets. Cambridge. Moore, D. M. (1957). The status of Viola lactea pp. 97-101 in Progress in the the British flora. BSBI, London. Moore, D. M. (1958). Journal of Ecology 46: 527-535. Moore, D. M. (1959). Evolution 13: 318-332.

Author

Study of

D. M. Moore, January 1998.

9. Viola lactea / V. riviniana Distinguishing features of these species can be deduced from the Tables in 7 and 8 above. Whilst the artificial interspecific hybrid, which is morphologically intermediate between the parents, is of low pollen-fertility (see Moore 1959, cited above), the species come into rather close contact throughout much of the range of V. lactea. Natural hybrids, with various admixtures of the parental characters, occur widely in Britain (and Portugal). Introgressive hybridisation leads to increased predominance of V. riviniana characteristics as its more closed habitats encroach on the open heathlands favoured by V. lactea. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Author

D. M. Moore, January 1998.

10. Viola canina / V. persicifolia Two subspecies of Viola canina L. occur in the British Isles. Subsp. canina is widespread in Britain and Ireland on dry and wet heaths, on fens and in sand dunes whilst subsp. montana is confined to fens in Huntingdonshire (V.c. 31) and Cambridgeshire (V.c. 29). The most useful characters for separating the three taxa are given in the Table below. In England, Viola persicifolia (V. stagnina Kit.) is now found only at Woodwalton Fen (V.c.31), Wicken Fen (V.c. 29) and Otmoor (V.c. 23) although previously it was more widespread, occurring as far north as south-west Yorkshire. In Ireland it is found in fens around the edges of turloughs in at least six Vice-counties.

V. canina L. subsp. canina

V. canina L. subsp. montana (L.) Hartm.

V. persicifolia Schreb.

Habit

Stems decumbent to erect

Stems erect

Rhizomes/roots creeping underground and sending up stems at intervals

Leaves

Ovate to ovatetriangular, less than 2 × as long as wide

Ovate-lanceolate to triangular, c. 2 × as long as wide

Triangular-lanceolate, less than twice as long as wide

Leaf colour

Bright green

Dark green

Light green

Leaf texture

Thick

Thick

Thin (translucent)

Stipules

Rarely long, on middle leaves less than 1/3 as long as petiole

M iddle leaf stipules ½ as long as petiole

Stipules usually ½ as long as petiole, but variable

Corolla

7-18 mm, deep or bright blue; petals obovate

15-22 mm, pale blue; petals oblong, large

10-15 mm, appearing almost circular in front view; white or pale blue; petals obovateorbicular

Corolla spur

Usually yellowish, c. twice as long as calyx appendages

Usually greenish, curved upwards

Greenish, obtuse; not or scarcely longer than calyx appendages

Hybrids between V. canina and V. persicifolia are frequent at some sites (e.g. Woodwalton Fen). Plants are intermediate between the parents in leaf characters but the flowers resemble more the V. canina parent. They usually have creeping underground stems and in this character resemble V. persicifolia. The hybrid is vigorous, often taller than either parent and is thought to be quite sterile. In Ireland, Praeger (1932) noted that while V. persicifolia occupies the lowest and wettest position around the edges of the turloughs, the hybrid with V. canina is found on slightly drier ground. Woodell (1965) noted a similar distribution of plants at the Oxfordshire site, Viola canina occupying the drier parts of fields, V. persicifolia and hybrids occupying the wetter areas. Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Gregory (1912) noted that “ intermediates (which have the appearance of hybrids) abound at Woodwalton”. She described V. canina × montana and V. montana × stagnina and went on to say that “ a goodly number of these fen plants show traces of being intermediates (or hybrids) between V. canina, V. stagnina and V. montana”. References

Gregory, E. S. (1912). British Violets. Cambridge. Praeger, R. Ll. (1932). Proc. Roy. Irish Acad. 41B: 37-45. Woodell, S. R. J. (1965). Proc. BSBI 6: 32-36.

Author

T. C. E. Wells, January 1998.

11. Viola palustris subspecies Two subspecies can be recognised within V. palustris L. though they are connected by intermediates. Plants clearly referable to either subspecies should be recorded as such, and intermediate plants as ‘intermediate’. Subsp. palustris is widespread. Subsp. juressi occurs mainly in the south and west of England and Wales, and in Ireland (see Critical Supplement).

Leave s

Subsp. palustris

Subsp. juressi (Link ex Wein) P. Fourn.

All obtuse

Summer leaves subacute, or shortly and bluntly acuminate

Petiole Glabrous s

Usually with spreading hairs

Bracts

Below middle of peduncle

At about the middle of peduncle

Spur

Slightly longer than sepal appendages

Longer than sepal appendages

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib NUPHAR / NYMPHAEA / NYMPHOIDES, VEGETATIVE AND FRUITING MATERIAL When there are no flowers, the genera of water-lilies can still be separated by either leaves or fruit capsules, which are frequently washed up on the shoreline. Leaves 1 Lateral veins of leaves arranged ± like a herring bone, branching dichotomously (the branches sub-parallel and separate from each other; Fig. a); petiole angled (trigonous in N. lutea, compressed in N. pumila); thin translucent underwater leaves present Nuphar 1 Lateral veins mostly radiating from the point of insertion of the petiole, breaking into a reticulum towards the edge of the leaf; petiole terete; translucent underwater leaves absent 2 2 Leaves 4-30 cm, the margin entire or at most slightly wavy, the basal lobes rounded or more or less angled (Fig. b); leaves all arising from the base; lower side of leaf without brownish dots Nymphaea 2 Leaves 2-14 cm, the margin slightly scalloped, the basal lobes rounded (Fig. c); leaves arising from the base, or from long trailing stems where they are often grouped; brownish dots present on lower side of leaf Nymphoides

Leaves (a) Nuphar lutea, (b) Nymphaea alba, (c ) Nymphoides peltata. Not to scale.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Pdfs created by Chris Barron.

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Plant Crib Fruits Nuphar: Fruit capsules flask-shaped or pear-shaped, the surface smooth or slightly ridged, topped by a receptacular disc with radial stigmatic ridges. Nymphaea: Fruit capsules ± globose, the surface covered with transverse scars left by the petals and stamens, topped by a receptacular disc with radial stigmatic ridges. Nymphoides: Fruit capsules ovoid with an acute apex prolonged into a beak. Author

N. F. Stewart, February 1988, revised 1997.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales Plant Crib edited T. C. G. Rich & A. C. Jermy. Pdfs created by Chris Barron.

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Plant Crib

ZOSTERA Zostera species grow on fine gravel, sand or mud, from half-tide mark down to about 4 m depth in the sea, the three species varying in their exposure ranges. Because of the comparative inaccessibility of the habitat they are somewhat neglected by recorders, but leaves and sometimes plants are regularly washed along the tide line. Only record rooted plants or those which if washed up occur in such freshness and quantity that they must be rooted nearby. There should be relatively little difficulty in identifying material from optimal habitats, but material growing on exposed mud flats or in sites subject to large tidal range and race, such as the Severn Estuary, is more difficult to identify (Evans 1985). Flowering stems of Z. noltei are easiest to separate because of the regularly spaced flaps (retinaculae) in its inflorescence (see Fig. a). The larger specimens of Z. marina cause little problem as they have large rhizomes and leaves wider than 4 mm. The branched fruiting stem of Z. angustifolia separates it from Z. noltei, and from Z. marina provided its leaves are narrower than 2 mm wide. In the Severn Estuary, Z. marina has leaves frequently 2 mm wide and then it is impossible to say which is Z. angustifolia and which is Z. marina. The result of exposure is to concertina the size characteristics so that it is not easy to distinguish the species. Exposure tends to result in a reduction of leaf width in Z. marina and a reduction of inflorescence length in all species. The following Table is based on the descriptions in CTM, Evans (1985) and M adden, Jennings & Jeffrey (1993). Note that apart from the larger specimens of Z. marina, the rhizomes gradate upwards in size depending on the covering of mud (do older, well-buried rhizomes give rise to younger and less thick ones?) and when plants grow together it is not easy to separate the brittle, twisted rhizomes. Seeds taken out of the same inflorescence have shown both smooth and ribbed surfaces (Evans 1985). M any characters overlap in size and identification should be made on a combination of characters.

a

b

Retinaculae (flaps) in inflorescences (a) Z. noltei, present (b) Z. marina, absent.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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Plant Crib Zostera noltei Hornem.

Zostera angustifolia (Hornem.) Rchb.

Zostera marina L.

0.5-1 mm thick; cortex with vascular bundles in its innermost layers

1-2 mm thick; cortex with 2 vascular bundles in its outer layers

2-5 mm thick; cortex with 2 vascular bundles in its outer layers

Leaves of (4-)6-20(>20) cm sterile long × up to 1 mm shoots wide; tip emarginate

15-30 cm long × 2 mm wide in summer (shorter and c. 1 mm wide in winter); tip obtuse and rounded when young, emarginate later

20-50(-200) cm long × (2-) 5-10 mm wide; tip rounded and mucronate when young, sometimes emarginate later where exposed

Leaves of (not stated) fertile shoots

4-15 cm long × 2-3 mm wide

Shorter and narrower, sometimes emarginate

Sheaths

Open

Closed when young (splitting later)

Closed when young (splitting later)

Flowering Simple or with 1-2 stems branches near base

10-30 cm, branched

Up to 60 cm, much branched

Inflorescence

3-6 cm in sheltered areas, averages below 2 cm when exposed

8-11 cm in sheltered areas, averages below 2.5 cm when exposed

(4-)9-12(-14) cm, in sheltered areas, averages 5 cm when exposed

Retinacul ae

Present (Fig a.)

Absent

Absent (Fig. b)

Stigma

Shorter than style

About as long as style

1-2 × style

Seeds

c. 2 mm

2.5-3 mm

3-3.5 mm

Rhizome s

Some authors suggest that Z. angustifolia auct. should be treated as a variety of Z. marina (e.g. Sell & M urrell 1996). Recent maps of all three species in Britain are given in the Scarce Plants. References Evans, T. G. (1985). BSBI Welsh Bulletin 41: 27-28. M adden, B., Jennings, E. & Jeffrey, D. W. (1993). Irish Naturalists’ Journal 24: 303-310. Author

T. G. Evans, January 1988, updated November 1997.

Botanical Society of the British Isles in association with National Museums & Galleries of Wales P lant Crib edited T. C. G. Rich & A. C. Jermy. P roduced by M. D. B. Rich.

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