Family: Asteraceae
Cirsium
Citation:
Miller, Gard. Dict. edn 4 (1754).
Derivation: Latinised Greek cirsion, applied by Pliny to a species of thistle.
Synonymy: Not Applicable Common name: Thistles.
Description:
Spiny biennial and perennial herbs; vestiture cobwebby; stems erect, often with spiny wings; leaves alternate, basal and cauline, dentate to pinnatisect.
Capitula sessile or pedunculate, solitary or in corymbs, homogamous; involucres globose to campanulate; bracts rigid, herbaceous, tipped with a single spine, imbricate in many unequal series; receptacle with bristle-like scales; florets all tubular, bisexual, or unisexual and the plants dioecious; corolla narrow, slightly widened upwards, 5-lobed, purple; anthers sagittate or tailed at the base, with subulate sterile appendages at the apex; style branches diverging at the apex only, without appendages.
Achenes oblong, asymmetric, glabrous; pappus of numerous plumose bristles connate in a ring at the base and deciduous as a unit.
Distribution:
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About 275 species in Europe, Asia and North America.
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Biology:
No text
Key to Species:
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1. Upper leaf surface cobwebby; capitula numerous in a corymbose panicle |
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C arvense 1. |
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1. Upper leaf surface hispid; capitula 1-3 at the end of each leafy branch |
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C vulgare 2. |
Author:
Not yet available
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