Annual, glabrous, milky herbs, 15-70 cm high; lower leaves oblanceolate or spathulate, lobed or undivided; middle leaves often runcinate-pinnatifid, sometimes entire; basal leaves up to 22 cm long, dentate or subspinose at margins, auricles rounded, stem clasping, entire or pinnatifidly toothed; heads homogamous, terminal, crowded in subcorymbose umbels or panicles on long peduncle; involucres ovoid, campanulate or cylindric, often dilated, thickened, conic at the base; bracts many seriate, herbaceous, ovate-lanceolate, glabrous, outer smaller; receptacle flat, naked; all florets ligulate, 5-fid, pubescent; achenes brown, 2-3 mm long, ovoid, obovoid or ellipsoid, compressed, 3-ribbed, obscurely muricate between the smooth or transversely rugose ribs; pappus longer than achenes, hairs many seriate, slender, silky, white.