Plants 30-150 cm. Corms sub-globose. Stems puberulent (at least distally, sometimes glabrous proximally). Leaves: basal and proximal cauline 1-nerved, elliptic- to oblanceolate-spatulate, 120-300 × 25-50(-55) mm, abruptly, gradually, or little reduced distally, essentially glabrous, weakly, if at all, gland-dotted. Heads in racemiform arrays. Peduncles usually (ascending) 10-50 mm. Involucres campanulate to turbinate-campanulate, 11-15 × (12-)15-22(-25) mm. Phyllaries in (3-)4-5 series, (erect or outer sometimes spreading-reflexing) oblong-obovate to broadly obovate (not bullate), unequal, glabrous or minutely puberulent, margins usually with relatively narrow, hyaline borders, apices broadly rounded. Florets 19-80; corolla tubes usually pilose inside, sometimes glabrous (Arkansas, Illinois, Missouri). Cypselae 4.5-6(-6.5) mm; pappi: lengths ± equaling corollas, bristles barbellate.
Glabrous or hairy, 3-8(-10) dm; lowermost lvs mostly 10-35 cm, long-petiolate, with elliptic to linear-elliptic or broadly oblanceolate blade; heads seldom more than 20(-35), subsessile or more often ascending on arcuate or sometimes spreading peduncles to 5 cm; invol ±hemispheric, 9-17 mm, its bracts appressed to more often loose or sometimes distally squarrose, broadly rounded, often anthocyanic distally, the middle ones only narrowly or not at all scarious-margined, often ciliolate but not erose-lacerate, the innermost ones sometimes more obviously scarious and erose; fls (21-)25-80 per head; cor-tube ±hairy toward the base (or near the middle) within; pappus strongly barbellate; 2n=20. Prairies, open woods, and other dry, open places; Me. to Mich., s. to Pa., Mo., Ark., and in the mts. to n. Ga. Aug., Sept. Three vars.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.