Annual or perennial herbs, rarely shrubs or small trees. Leaves alternate, usually oblanceolate, entire to dentate or pinnately lobed. Heads heterogamous, rather small, several to numerous in corymbs or panicles, rarely solitary, disciform or rarely short radiate. Receptacle flat or subglobose, naked or alveolate. Involucre campanulate to somewhat urceolate, bracts 2-4 seriate, more or less imbricate, scarcely herbaceous, soon widely spreading. Florets numerous, corolla very slender. Outer florets pistillate, numerous in many rows, corolla tubular, filiform; sometimes with a narrow, white or purplish, minute ligule, surpassed by pappus; style branches nearly linear, nearly glabrous to glandular puberulent. Disc florets bisexual, or sometimes partly functionally staminate, usually few, tubular, (4-)5-lobed. Achenes obovoid-oblong, sometimes compressed, mostly pubescent. Pappus of many, fine, mostly fragile bristles.
About 60 species, mainly tropical and subtropical, in both the Old and New Worlds. In Taiwan, six species, one of which is represented by two varieties.