Perennials, 20-100 cm. Stems usually 1, unbranched or sparingly branched distally, weakly to moderately winged, glabrous proximally, sparsely to moderately hairy distally. Leaves glabrous or sparsely hairy; basal blades oblanceolate to spatulate, entire or undulate to undulate-serrate; proximal and mid blades oblanceolate to lanceolate, usually entire, sometimes undulate to undulate-serrate; distal blades lance-linear, entire. Heads 1-10 per plant, borne singly or in paniculiform to corymbiform arrays. Peduncles (3-)6-11(-15) cm, sparsely to moderately hairy. Involucres hemispheric to globoid, 10-15 × 10-20 mm. Phyllaries (connate proximally) sparsely to moderately hairy. Ray florets 9-24, neuter; corollas yellow, 12.5-21 × 4-8 mm. Disc florets 200-500(-800+); corollas yellow proximally, usually purple to yellow or yellow-brown distally, 4-5.6 mm, lobes 5. Cypselae 1-1.4 mm, sparsely to moderately hairy; pappi of 6-8 entire, non-aristate scales 1-1.7 mm. 2n = 26, 28. Flowering Mar-May. Ditches, fields, other moist areas such as wet woods, bogs, and swamp edges; 0-80 m; Ala., Fla., Ga., La., Miss., N.C., Va.
Fibrous-rooted perennial 3-8 dm, glabrous or merely atomiferous-glandular below, the peduncles and involucres loosely puberulent; lvs relatively few, the basal tufted and generally persistent, oblanceolate or elliptic, usually petioled, 2-17 cm overall and 0.6-2(-3) cm wide; cauline lvs few, reduced, seldom exceeding the internodes, narrowly decurrent; heads 1-3(-6), naked-pedunculate, the disk hemispheric to subglobose, 1-2 cm wide, usually purple-brown or red-brown; rays ca 8 to ca 13, neutral, 1-2.5 cm, trilobed; pappus of 5-10 awnless, often distally rounded scales 1-1.7 mm; 2n=26, 28. Swampy or boggy places and moist pine woods; se. Va. to Fla., La., and Tenn. May, June. (H. curtisii, the rare form with yellow disk)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.