Syn. Gen. Compos., 221. 1832. 1832
Perennials, to 30 cm. Stems prostrate to decumbent, branched throughout. Leaves cauline; opposite; petiolate; blades (± 3-nerved) deltate to ovate or lanceolate, bases cuneate to truncate, margins toothed, faces ± scabrellous. Heads radiate, borne singly (in axils). Involucres obconic, 3–8 mm diam. Phyllaries persistent, 5 in 1(–2) series (linear to lanceolate, herbaceous). Receptacles convex, paleate (paleae persistent, scarious). Ray florets 3–8, pistillate, fertile; corollas pale yellow. Disc florets 10–20, bisexual, fertile; corollas yellow, tubes shorter than funnelform throats, lobes 4–5, ± deltate. Cypselae compressed or flattened, cuneate (faces often tuberculate); pappi persistent, of 2(–5+) stout awns. x = 12.
s United States, Mexico, Central America.
Species 2 (1 in the flora).