Annuals, mostly 100-200(-400) cm. Leaves: petioles 3-8 cm; blades ± deltate to pentagonal, 7-38 × 7-30 cm, sometimes 3- or 5-lobed, abaxial faces glabrous or soft-pubescent. Peduncles 11-27 cm. Phyllaries 14-21 in (2-)3 series, lanceolate to linear; outer 17-30 × 4-7.5 mm, apices acute, abaxial faces usually densely puberulent; inner 16-28 × 5-8 mm, apices rounded to acute, abaxial faces usually densely puberulent. Paleae 11.5-15 × 2-3 mm, mucros 2.5-5.5 mm. Ray florets 8-13; corollas usually orange, sometimes yellow, laminae oval to oblong, 20-33 × 6-17 mm. Disc florets 60-90. Cypselae 5-7. 2n = 34.

Flowering Nov.-Jan. Disturbed sites; 0-20+ m; introduced; Fla., La.; Mexico; West Indies; Central America.

Tithonia rotundifolia is widely cultivated in warm climates and may persist after plantings (e.g., in Asia).