Time of bloom: Late July to September.
Seed-time: August to October.
Range: Massachusetts to Minnesota and Nebraska, southward to Florida and Texas. Habitat: Roadsides, borders of fields, waste places.
Root thickened, deep-boring, and winter rosettes very large. Stem three to ten feet in height, branching, downy-hairy. Leaves oblong lance-shaped, the lowermost sometimes pinnatifid into triangular lobes, with short, margined petioles, but those above wavy-edged and prickly-toothed, sessile or somewhat clasping but not decurrent, dark green and rough-hairy above, white-woolly beneath. Heads solitary, terminal, about two inches broad, light purple, the outer bracts of the involucre with a dark, glandular spot on the back and tipped with spreading spines; the inner scales without prickles. Achenes dark brown, numerous, with copious, white, plumose pappus.
Means of control the same as for the Spear Thistle.