Annuals, biennials, or short-lived perennials, 4-80 cm; fibrous-rooted, caudices simple. Stems erect (green proximally, leafy to arrays), hirsuto-villous to villous proximally, loosely strigose to sparsely hirsute distally, minutely glandular. Leaves basal (persistent or withering by flowering) and cauline; basal blades oblanceolate to obovate, (15-)30-110(-150) × 10-25(-40) mm, margins shallowly crenate to coarsely serrate or pinnately lobed, faces sparsely hirsute to villous, eglandular; cauline blades oblong-oblanceolate to lanceolate, gradually reduced distally (bases clasping to auriculate-clasping). Heads (1-)3-35 usually in corymbiform arrays (ultimate branches arising near stem tips). Involucres 4-6 × 6-15 mm. Phyllaries in 2-3 series (sometimes basally connate), hirsuto-villous to sparsely hirsute or glabrous, sometimes minutely glandular. Ray florets 150-250(-400); corollas usually white, sometimes pinkish, 5-10 mm, laminae not coiling or tardily coiling. Disc corollas 2.1-3.2 mm. Cypselae 0.6-1.1 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 15-20(-30) bristles.
Biennial to short-lived perennial 2-7 dm, pubescent with long, spreading hairs, varying to subglabrous; basal lvs narrowly oblanceolate to obovate, coarsely crenate-toothed or lobed, rounded above, seldom over 15 נ3 cm; cauline lvs clasping, mostly oblong or ovate, ±reduced; heads 1-many; invol 4-6 mm, ±hirsute with flattened hairs, or subglabrous; disk 6-15 mm wide; rays mostly 150-400, 5-10 mm, 0.5 mm wide or less; deep pink or rose-purple to white; disk-cors 2.5-3.2 mm; achenes 2-nerved; pappus of ca 20-30 bristles; 2n=18. Various habitats, widespread in N. Amer., and throughout our range, somewhat weedy, varying in size with the habitat. (E. purpureus; E. provancheri)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.