Perennials, 20-60 cm. Stems usually 1, usually unbranched distally, moderately to strongly winged, glabrous proximally, glabrous or sparsely hairy distally. Leaves glabrous; basal blades narrowly obovate to narrowly oblanceolate, usually entire, sometimes undulate-serrate; proximal and mid blades narrowly lanceolate, usually entire, sometimes undulate-serrate; distal blades lance-linear, usually entire, rarely undulate-serrate. Heads 1(-3) per plant, usually borne singly. Peduncles 10-30 cm, sparsely hairy. Involucres hemispheric to globoid, 10-18 × 15-25 mm. Phyllaries sparsely to moderately hairy. Ray florets 13-30, neuter; corollas yellow, 14-25 × 4-10 mm. Disc florets 250-650(-1000+); corollas yellow, 4.3-5.4 mm, lobes 5. Cypselae 1.2-1.5 mm, moderately hairy; pappi of 5-12 deeply lacerate, non-aristate scales 2-3.7 mm. 2n = 32. Flowering (Mar-)Apr(-May). Ditches, other moist areas such as wet woods, bogs, and swamp edges; 10-50 m; Ark., La., Tex.