Cirsium horridulum Michx.

• Authority

  Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

• Family

  Asteraceae

• Scientific Name

  Cirsium horridulum Michx.

• Description

  Species Description - Stout biennial 2–15 dm, simple or with short, stout, ascending, peduncle-like branches, some of the roots commonly fleshy-thickened; herbage thinly tomentose and eventually generally glabrate, or the lvs merely arachnoid and glabrate; lvs strongly spiny, broad and pinnatifid to seldom narrow and merely spiny-toothed, the largest ones at or near the base; heads light yellow or white to lavender or purple, several or solitary, each subtended by a number of narrow, erect, strongly spiny, reduced lvs; invol (2.5–)3–5 cm, the outer bracts with erect spine-tip, the inner merely attenuate, all with modified, shortly scabrous or scabrous-ciliate margin; achenes 4–6 mm; 2n=32, 34. Open places, especially in sandy soil or along salt or fresh marshes; coastal states (and Pa.) from Me. to Fla. and Tex.; Mex. May–Aug. (C. spinosissimum) Ours are the widespread var. horridulum.

• Common Names

  yellow thistle