Annual bush sunflower

Simsia exaristata A. Gray

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).