Perennials, to 120 cm (stoloniferous, rosettes forming at stolon apices). Stems glabrous or moderately hirsute (branches spreading). Leaves: blades lanceolate to broadly ovate or elliptic (not lobed), herbaceous, bases attenuate to cordate, margins usually entire or serrate, sometimes lacerate, apices acute, faces glabrous or hirsute to strigose; basal petiolate, 5-30 × 1-8 cm; cauline petiolate, 2-25 × 0.5-7 cm, bases attenuate to cordate or auriculate. Heads borne singly or (2-7) in corymbiform arrays. Phyllaries to 2 cm. Receptacles hemispheric to ovoid; paleae 2.5-4 mm, (apical margins usually ciliate) apices obtuse to acute, abaxial tips usually glabrous. Ray florets 10-15; laminae elliptic to oblanceolate, 15-25 × 3-6 mm, abaxially strigose. Discs 12-16 × 10-18 mm. Disc florets 50-500+; corollas proximally yellowish green, brown-purple distally, 3-4.2 mm; style branches ca. 1.3 mm, apices rounded. Cypselae 2.2-4 mm; pappi coroniform, to 0.2 mm.
Perennial 3-10 dm, commonly stoloniferous, sparsely to moderately hairy, seldom densely hirsute; lower lvs lanceolate to cordate, long-petiolate, the others similar or gradually reduced, short-petiolate or sessile; heads commonly long-pedunculate, the hemispheric or ovoid disk dark purple or brown, 10-18 mm wide; rays 8-21, yellow to orange; receptacular bracts obtuse or acute, smooth or ±ciliolate-margined, rarely with a few appressed hairs on the back; pappus an inconspicuous low crown; 2n=38, 76. Chiefly in woods or moist places; Pa. to Mich., Ill., and s. Mo., s. to Fla. and Tex., and occasionally adventive elsewhere, as in Conn. July-Oct. Three morphologically and geographically overlapping regional vars. that seem sharply distinct at some points of contact:
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.