Perennials, (10-)20-80(-120) cm (fibrous-rooted, usually with caudices, sometimes rhizomatous). Stems erect, sometimes branched (striate). Leaves basal and/or cauline; alternate; petiolate or sessile; blades (1- or 3-nerved) elliptic, linear, linear-elliptic, linear-oblanceolate, oblanceolate, ovate, or spatulate, margins entire, faces glabrous. Heads discoid, borne singly or in open, corymbiform arrays (peduncles relatively long). Involucres hemispheric to obconic, 10-25+ mm diam. Phyllaries persistent, 12-24 in ± 2 series (lanceolate, linear, oblong, ovate, or rhombic, subequal, herbaceous, midnerves often keeled, proximal margins often scarious). Receptacles conic or convex (usually hollow), paleate (paleae linear to spatulate, distally herbaceous). Ray florets 0. Disc florets (20-)45-90(-160+), bisexual, fertile; corollas pale lavender, pink, or purple, or white, (usually hairy) tubes longer than to nearly equaling throats, lobes 5, lance-linear to linear-oblong (often contorted). Cypselae turbinate or clavate (5-angled, ribs 10, often hairy); pappi persistent, of 5(-6) scarious to membranous (hyaline, sometimes scaberulous) scales. x = 9.
Heads discoid, the fls all tubular and perfect, with slender, elongate, hairy, conspicuously lobed, white or more often anthocyanic cor; invol of 1 or 2 series of narrow, subequal, ±herbaceous bracts; receptacle conic or convex, chaffy, its bracts linear to linear-spatulate, commonly herbaceous distally; style-branches flattened, elongate, with short, minutely hairy appendage; achenes 5-angled, 10-ribbed, the ribs commonly hairy; pappus of 5(6) short, scarious or hyaline scales; perennial herbs with alternate (or all basal) entire lvs and long-pedunculate, broadly campanulate heads. 8, mainly se. U.S.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.