Plants (40-)60-120(-180) cm. Corms globose, sometimes becoming elongate rhizomes. Stems glabrous or densely piloso-puberulent. Leaves: basal and proximal cauline 3-5-nerved, linear to narrowly oblanceolate or oblanceolate, 110-220 × 4-10(-12) mm, gradually then abruptly reduced distally (bractlike proximal to heads), essentially glabrous or sparsely pilose to densely piloso-puberulent, weakly gland-dotted (bases of basal usually fibrous-persistent). Heads in dense, spiciform arrays. Peduncles usually 0, rarely (spreading to ascending) 1-2 mm. Involucres campanulate-cylindric, 7-9(-10) × 3.5-5 mm. Phyllaries (reflexed or curving-spreading) in 4-5 series, oblong-lanceolate, unequal, essentially glabrous or ± pilose, margins with hyaline borders, sometimes ciliate, apices usually acute to acute-acuminate (sometimes distally dilated, nearly petaloid). Florets (4-)5-8; corolla tubes glabrous inside. Cypselae 3.8-4.5(-5) mm; pappi: lengths ± equaling corollas, bristles barbellate.
Strict, 5-15 dm, ±hirsute in the infl (including the axis) or throughout, seldom glabrous; lvs numerous, linear or nearly so, the lower ones 10-50 cm נ3-13 mm, the others reduced upward; heads sessile, crowded in an elongate, densely spiciform infl; invol subcylindric or narrowly turbinate, 8-11 mm, its bracts tapering to an acuminate, conspicuously squarrose tip, or the inner ones sometimes blunter and loosely erect; fls 5-7(-12) per head, the cor 7-9 mm including the 2-2.5 mm lobes, glabrous or very nearly so within; pappus barbellate; 2n=20, 40. Moist or dry prairies and open woods; Ind. and Ky. to Minn., N.D., Tex., and Miss., and intr. e. to N.J. and w. N.Y. July-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
