Perennials, subshrubs, or shrubs, to 250(-500) cm. Leaves: petioles 2-6 cm; blades ± deltate to pentagonal, 7-33 × 7-22 cm, sometimes 3- or 5-lobed, abaxial faces glabrous to hispid-pilose. Peduncles 7-24 cm. Phyllaries 16-28 in (3-)4 series, oblong to ovate; outer 6-10 × 4-7 mm, apices rounded to acute, abaxial faces usually glabrous; inner 10-20 × 3-10 mm, apices rounded to acute, abaxial faces glabrous. Paleae 10-13 × 2-3 mm, mucros 1.5-2.5 mm. Ray florets 7-14; corollas yellow, laminae linear, 48-69 × 9-16 mm. Disc florets 80-120+. Cypselae 4-6 mm. 2n = 34.
Flowering Sep-Jan. Disturbed sites; 0-20+ m; introduced; Fla., Tex.; Mexico; also introduced in West Indies, Central America, Asia, Africa, Atlantic Islands, Indian Ocean Islands, Pacific Islands, Australia.
Tithonia diversifolia is widely cultivated in warm climates and may persist after plantings; a report for Louisiana was not confirmed for this treatment.