Family: Asteraceae
Carduus
Citation:
L., Sp. Pl. 820 (1753).
Derivation: Latin carduus, a name applied by the Romans to various species of thistles.
Synonymy: Not Applicable Common name: Thistles.
Description:
Spiny annual and perennial herbs; stems erect, with spiny wings; leaves basal and cauline, alternate, dentate to pinnatisect.
Capitula terminal, solitary or sessile in dense clusters, cylindrical to depressed-globose, homogamous; involucres cylindrical to broadly hemispherical; bracts rigid, herbaceous, spinetipped, imbricate in many unequal series; receptacle densely hairy; florets all tubular, bisexual, fertile; corolla narrow, only slightly widened upwards, 5-lobed, purple to pink; anthers sagittate at the base, with acute appendages at the apex; style branches linear, flattened, diverging at the apex only, without sterile appendages.
Achene ovoid, glabrous, striate; pappus of numerous barbellate bristles connate in a ring at the base and deciduous as a unit.
Distribution:
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About 95 species in Europe, Asia and Africa.
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Biology:
No text
Key to Species:
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1. Capitula hemispherical, 2-4 cm diam.; corollas c. 20 mm long |
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C. nutans 1. |
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1. Capitula cylindrical, c. 1 cm diam.; corollas 10-15 mm long |
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2. Capitula on short terete peduncles; intermediate bracts of the involucre with thickened minutely hairy margins |
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C pycnocephalus 2. |
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2. Capitula completely sessile; intermediate bracts of the involucre with glabrous scarious margins |
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C tenuiflorus 3. |
Author:
Not yet available
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