Perennials, mostly 30-200 cm. Stems prostrate, branched ± throughout (rooting at nodes, usually ± succulent). Leaves cauline; opposite; sessile or petiolate; blades (usually 3-nerved) mostly trullate to lanceolate, often obscurely 3-lobed, bases ± cuneate, margins entire or toothed, faces usually scabrous. Heads radiate, borne singly. Involucres obconic, 6-12 mm diam. Phyllaries persistent, 12-15 in 2-3 series (outer larger, more foliaceous than inner). Receptacles convex to conic, paleate (paleae conduplicate, scarious, acute). Ray florets 4-10+, pistillate, fertile; corollas yellow to orange. Disc florets 30-60+, bisexual, fertile; corollas yellow to orange, tubes shorter than campanulate throats, lobes 5, lance-triangular. Cypselae strongly biconvex to plumply 3-4-angled (epidermes usually thick, corky, smooth or tuberculate, apices rostrate, each bearing central neck or boss, rostra obscure in mature fruits); pappi 0, or persistent, coroniform (erose or fimbrillate to lacerate, 0.1-0.6 mm). x = 15.