Taurian thistle, bull cottonthistle

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. Heads mostly borne singly at branch tips. Involucres ± spheric, 20–50 mm diam (excluding spines), base truncate to concave. Phyllaries lanceolate, bases 3–4 mm wide, glabrous or glandular-puberulent, sometimes ± cobwebby-tomentose, spines to 4 mm. Corollas purplish pink, 25–30 mm. Cypselae 5–6 mm; pappi of many whitish to tan, scabrous or minutely barbed bristles 8–10 mm. 2n = 34 (Russia).

Flowering summer (Jun–Sep). Grasslands, arid woodlands, riparian areas, roadsides, agricultural lands; 600–2200 m; introduced; Calif., Colo.; s Europe; sw Asia.

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.