Leaves: petioles 1-10(-30) mm; blades 10-40(-120) × 5-20(-60) mm, often 3-lobed. Cypselae 2-2.5 mm; pappi 4-5(-7.5) mm. 2n = 36. Flowering Jan-Dec. Disturbed sites; 0-10 m; introduced; Fla., Tex.; Mexico. Tridax procumbens is listed as a noxious weed for United States and is listed as a pest or noxious weed for nine or more states.