Flora of North America species comparison

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Onopordum acanthium

Onopordum tauricum

cotton thistle, onoporde acanthe, Scotch cotton-thistle, Scotch-thistle, Scots thistle

bull cottonthistle, Taurian thistle
Habit Plants 50–200 cm, herbage glandular-puberulent, sticky throughout.
Stems

wings 0.5–2 cm wide.
Leaves

10–30 cm, margins shallowly to deeply 1–2-pinnatifid, with 6–8 pairs of acutely triangular lobes, thinly arachnoid tomentose when young.
Involucres

± spheric, 20–50 mm diam (excluding spines), base truncate to concave.
Corollas

purplish pink, 25–30 mm.
Phyllaries

lanceolate, bases 3–4 mm wide, glabrous or glandular-puberulent, sometimes ± cobwebby-tomentose, spines to 4 mm.
Heads

mostly borne singly at branch tips.
Cypselae

5–6 mm;

pappi of many whitish to tan, scabrous or minutely barbed bristles 8–10 mm.
2n

= 34 (Russia).

Onopordum acanthium

Onopordum tauricum
Phenology Flowering summer (Jun–Sep).
Habitat Grasslands, arid woodlands, riparian areas, roadsides, agricultural lands
Elevation 600–2200 m (2000–7200 ft)
Distribution
from FNA
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
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CO; s Europe; sw Asia [Introduced in North America]
[BONAP county map]
Discussion

Subspecies 3 (1 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Taurian thistle is a noxious weed in California and Colorado. In southeastern Colorado it sometimes grows with Onopordum acanthium. Putative hybrids have been observed in this area.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 19, p. 88. FNA vol. 19, p. 88.
Parent taxa Asteraceae > tribe Cardueae > Onopordum Asteraceae > tribe Cardueae > Onopordum
Sibling taxa
O. illyricum, O. tauricum
O. acanthium, O. illyricum
Subordinate taxa
O. acanthium subsp. acanthium
Name authority Linnaeus: Sp. Pl. 2: 827. (1753) Willdenow: Sp. Pl. 3: 1687. (1803)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

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