Annuals, 70-200 cm. Leaves: petioles 0-3.3 cm; blades deltate, 7-28 × 5.5-21.5 cm, abaxial faces sparsely hirsute (hairs larger on veins). Peduncles 17-36 cm. Phyllaries 13-16 in 3 series, linear to spatulate; outer 8-15 × 2.5-4.5 mm, apices acute, abaxial faces puberulent; inner 12-15.5 × 3.5-7 mm, apices acute, abaxial faces glabrous. Paleae 11-16.5 × 2-4 mm, mucros 3 mm. Ray florets 7-10; corollas yellow, laminae oblong, 9-15 × 4-6 mm. Disc florets 40-60. Cypselae 6-9 mm. 2n = 34. Flowering Aug-Sep. Disturbed areas, canyons, watercourses; 900-1000 m; Ariz.; Mexico (Sonora).