Fls all ligulate and perfect, yellow; invol campanulate or narrower; achenes columnar to fusiform, but scarcely beaked, with a whitish basal callosity, ca 10-ribbed; pappus of 5–many members, these commonly with paleaceous base and slender, bristle-like tip, varying (in spp. approaching Agoseris) to merely obscurely flattened capillary bristles; lactiferous herbs with a taproot, entire to pinnatifid lvs, and 1–many heads on long naked peduncles. 25, chiefly w. U.S.
Capitula solitary on fistular scapes, many-fld, homogamous. Phyll. in 1 series, with a few bracteoles at base; receptacle nude, alveolate. Florets perfect, ligulate. Achenes us. glab., striate, not beaked; pappus-hairs dilated and paleaceous at base, barbellate above. Scapigerous herbs with milky juice. Genus of some 40 spp., mostly American, 1 sp. Australasian.