Annual or perennial herbs. Leaves opposite and/or alternate, sessile, entire, hairy. Inflorescence a compound head of 20–300 capitula; bracts subtending compound heads absent or inconspicuous and few, leaf-like or partly hyaline. General receptacle entire or branched, glabrous or hairy; capitula discoid, homogamous; capitulum-subtending bracts absent; capitular bracts in 2–3 rows, hyaline or scarious except for the midrib, margins entire, the upper part of the lamina often constricted and coloured; florets c. 1–20 per capitulum, bisexual; corolla tubular, 5-lobed, yellow; style branches truncate; stamens 5, anthers tailed. Cypselas glabrous or with globose, mucilage-producing hairs; pappus of basally connate, plumose bristles about as long as corolla-tube.