Onopordum acanthium |
Onopordum |
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cotton thistle, onoporde acanthe, Scotch cotton-thistle, Scotch-thistle, Scots thistle |
cotton-thistle, onoporde |
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Habit | Biennials, 50–400+ cm, coarse, prickly. | |||||||||
Stems | usually erect, ± branched, spiny-winged. |
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Leaves | basal and cauline; winged-petiolate (basal) or sessile (cauline); blade bases narrowing, margins pinnately lobed or divided and dentate, teeth and lobes tipped with stout spines. |
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Involucres | hemispheric to ovoid or spheric. |
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Receptacles | flat to convex, epaleate, not bristly, alveolate with apically fringed pits. |
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Florets | many; corollas white or purple, actinomorphic or weakly zygmorphic, tubes slender, throats cylindric or narrowly goblet-shaped, lobes linear; anther bases acute-tailed, apical appendages subulate; style branches: fused portions with minutely hairy nodes, long, cylindric, minutely papillate, distinct portions minute. |
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Phyllaries | many in 8–10+ series, linear to ovate, entire, tapered to stiff spines, middle and outer often spreading or reflexed. |
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Heads | discoid, borne singly or in corymbiform arrays; (peduncles 0 or spiny winged). |
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Cypselae | ± cylindric, 4–5-angled, usually ± transversely roughened, glabrous, attachment scars basal; pappi falling in ring, of many barbed or plumose bristles, basally connate. |
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x | = 17. |
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Onopordum acanthium |
Onopordum |
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Distribution |
AL; AZ; CA; CO; CT; DE; FL; IA; ID; IL; IN; KS; KY; MA; MD; MI; MN; MO; MT; NE; NJ; NM; NV; NY; OH; OK; OR; PA; RI; TX; UT; VA; VT; WA; WI; WV; WY; BC; NB; NS; ON; QC; Eurasia
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Eurasia [Introduced in North America] |
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Discussion | Subspecies 3 (1 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species 25–60 (3 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 19, p. 88. | FNA vol. 19, p. 87. | ||||||||
Parent taxa | Asteraceae > tribe Cardueae > Onopordum | Asteraceae > tribe Cardueae | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Name authority | Linnaeus: Sp. Pl. 2: 827. (1753) | Linnaeus: Sp. Pl. 2: 827. (1753): Gen. Pl. ed. 5, 359. (1754) | ||||||||
Web links |
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