Single-stemmed perennial 1-3 m from a short, stout rhizome, usually glabrous and somewhat glaucous; lvs mainly cauline, numerous, on evident petioles 0.5-3 cm, mostly trifoliolate, or the upper entire, the lfls lanceolate or narrowly elliptic, 5-10(-13) cm נ6-25(-30) mm, the terminal one often again divided; heads several or many, the disk to 1 cm wide, yellow, becoming purplish or deep red, its cors 5-toothed; outer bracts ca 8, linear-oblong, obtuse, 2-3 mm, the inner much broader and 2-3 times as long, more acute; rays yellow, 1-2.5 cm; receptacular bracts narrowly linear or linear-clavate; style-appendages cuspidately acute; achenes obovate, 4-7 mm; pappus of a few minute erect bristles, sometimes also with 2 short, upwardly barbed awns; 2n=26. Mostly in moist or wet low places and in woods; Mass. and s. Ont. to Wis., s. to Fla. and Tex. July-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.