Perennial or biennial prickly herbs, simple or few-branched. Leaves alternate, serrate-dentate or pinnatifid, often very spinescent. Heads large, heterogamous, many flowered, discoid, long-peduncled, florets uniform, bisexual. Involucre globose or ovoid, bracts in many series, appressed, erect, spreading or recurved, prickly tipped or unarmed. Receptacle flat or convex, densely bristly. Corolla slender, purple, pink, white or yellow, tube slender, limb equal or obliquely 5-lobed. Filaments hairy or rarely glabrous; anthers sagittate at base, auricles connate, lacerate. Style branches short, obtuse. Achenes glabrous, obovoid, obtusely 4-angled, glabrous, smooth or ribbed, truncate apically, base areolate, nearly straight. Pappus copious, bristles in many series, slender, feathery, deciduous with a basal ring.
About 250 species in Eurasia, northern and eastern Africa and North America; in Taiwan, nine species, one of which is represented by two varieties.