Annual to perennial herbs. Lvs opposite or verticillate, sometimes in basal rosettes, often lobed or toothed; stipules 0. Fls bracteate, usually small (florets) and borne in dense, many-flowered cymose capitula, ☿ or ♀, each with a basal epicalyx (involucel) of connate bracteoles which is often expanded distally into a corona, often subtended by a receptacular scale; marginal florets often radiate. Calyx epigynous, small, cupuliform, toothed or setose, pappus-like. Corolla epigynous, tubular, 4-5-lobed, subequal or 2-lipped, usually zygomorphic. Stamens (2)-4, epipetalous; filaments free or united in pairs; anthers 2-locular, dehiscing longitudinally. Ovary inferior, 1-locular, mostly adnate to the receptacle; styles slender; ovules solitary, pendulous. Fr. dry, enclosed in epicalyx and often surmounted by a persistent calyx.