Annuals (rarely persisting), 20-400 cm (taprooted or fibrous rooted). Leaves: petiole bases rarely dilated (not fused to form nodal discs), blades ovate to deltate, 2-21 × 1-16 cm, rarely 3-lobed. Heads in tight to loose, corymbiform arrays. Peduncles 0.5-10 cm. Involucres 8-12 × 5-10 mm. Phyllaries 13-19, unequal. Ray florets 5-10; corollas orange-yellow, laminae 5.1-12 mm. Disc florets 13-27; anthers yellow proximally, usually purple to bronze distally. Cypselae 4.2-6 mm; pappi usually 2.5-4.6 mm, rarely 0. 2n = 34.

Flowering year round (mostly Sep-Dec). Deserts, roadsides, open fields, borders of agricultural fields; 100-2200 m; Ariz., N.Mex., Tex.; Mexico; Central America (Guatemala).