Fibrous-rooted perennial 5-15 dm, glabrous to finely strigose or puberulent; lvs numerous, all or mainly cauline, lance-linear to elliptic or narrowly ovate, narrowed to a sessile or subpetiolar base, decurrent as wings on the stem, not much reduced upwards, 4-15 cm נ5-40 mm, the lower ones deciduous; heads (1-)several or many in a leafy infl, hemispheric or subglobose, the disk yellow, 8-20 mm wide; rays ca 13 to ca 21, pistillate, mostly 1.5-2.5 cm; pappus- scales generally brownish, ovate or lanceolate, tapering to a short awn, to ca 1 mm overall; 2n=32, 34, 36. Moist low ground; Que. to Fla., w. to B.C. and Ariz. Aug.-Oct. The var. autumnale, with elliptic to oblong or lanceolate, generally toothed lvs 3-6 times as long as wide, occurs from Conn. to Minn., s. to Fla. and Tex. (H. altissimum; H. latifolium; H. parviflorum) The var. canaliculatum (Lam.) Torr. & A. Gray, a usually smaller, sometimes single-headed plant with narrower, mostly subentire lvs 7-12 times as long as wide, occurs from Que. to N.Y., w. to Wis. Other vars. occur westward.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.