Plants 20-100 cm. Corms sub-globose (often knotty, densely fibrous-rooted). Stems sparsely to densely puberulent, puberulent-villous, or strigoso-puberulent. Leaves: basal and proximal cauline 1-nerved, narrowly ob-lanceolate to spatulate-lanceolate, 90-150(-220) × 4-17(-24) mm, gradually reduced distally to near midstem, then abruptly reduced, linear or narrowly lanceolate, ascending to nearly erect, bractlike, sparsely to densely puberulent, ± gland-dotted. Heads (4-21) in open, racemiform arrays (terminal heads sometimes maturing first and larger). Peduncles usually (5-)8-15(-30) mm. Involucres campanulate to turbinate-campanulate, 10-15 × 13-18 mm. Phyllaries in (3-)4-5 series, oblong-obovate to oblong-spatulate, strongly unequal, essentially glabrous, margins with (purple) hyaline borders, erose to lacerate or irregular, apices broadly rounded to truncate. Florets 30-70; corolla tubes glabrous inside. Cypselae 5-7 mm; pappi: lengths ± equaling corollas, bristles barbellate. 2n = 20. Flowering Jul-Oct. Prairies (often wet), pine barrens, clearings in aspen and pine woods, ridges along lake shores, depressions in granite, rocky slopes, roadsides, ditches, along railroads, sand, clay; 100-2400 m; Alta., Man., Sask.; Colo., Iowa, Minn., Mont., N.Mex., N.Dak., S.Dak., Wis., Wyo.
Plants 2-11 dm, usually glabrous below the infl; lvs 8-100 below the infl, the lowest ones 8-27 נ0.5-4 cm, the others rather abruptly reduced and becoming sessile; heads (1-)3-10(-35), evidently pedunculate to occasionally subsessile, the terminal one obviously the largest; invol 13-20 mm, broadly campanulate or hemispheric, glabrous, its bracts seldom much squarrose, with conspicuous, lacerate, scarious margins, seldom at all crisped, often purplish upwards; fls 30-100 per head; cor glabrous within; pappus barbellate; 2n=20. Mostly in damp, low places, occasionally in drier soil; Wis. to Alta., Colo., and N.M. Aug., Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.