Heads radiate, the rays pistillate, yellow or white, or rarely wanting and the heads discoid; invol bracts in 1 or 2 series, subherbaceous and subequal; receptacle elongate, conic or subcylindric, its bracts clasping the disk-achenes and eventually deciduous with them; disk-fls perfect and fertile style-branches flattened, truncate, exappendiculate; achenes of the rays 3-angled or tangentially flattened, those of the disk radially flattened, commonly ciliate-margined; pappus of 1–3 slender setiform awns, or none; annual or rarely perennial herbs with opposite, commonly toothed lvs. 40, mainly warm reg.
Perennial herbs. Leaves opposite and decussate, 3–5-veined from base. Capitula axillary or terminal, solitary, ovoid, discoid; phyllaries 2–3-seriate, subequal; receptacle paleate. Disc florets many, bisexual, 5-lobed; style with bulbous base. Achenes compressed, with a cork-like margin; pappus of 1–4 awns