Fls all ligulate and perfect, yellow; invol campanulate or ovoid-urceolate, the inner bracts uniseriate, subequal, after anthesis becoming thickened and often clasping the achenes; outer bracts narrow and successively shorter, or sometimes uniseriate, broad and foliaceous; achenes subterete, angled, or somewhat compressed, often incurved, commonly 5-10-ribbed (sometimes obscurely so), tending to be transversely rugulose; pappus of plumose bristles, commonly with some outer, shorter, merely barbellate members, the outer achenes sometimes with the pappus reduced or obsolete; lactiferous herbs with alternate or all basal, entire to pinnatifid lvs. 40, temp. Eurasia, n. Afr.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
