Plants 30-250 cm, glabrous or sparsely hispid. Leaves: petioles 1-7 cm; blades 10-20 cm, ultimate lobes 2-10 mm wide, margins spinulose-ciliate, apices acute, often mucronulate. Peduncles 10-30 cm. Calyculi of usually spreading, linear-subulate bractlets 6-10 mm, apices acuminate. Involucres 5-15 mm diam. Phyllaries erect, oblong-lanceolate, 7-11 mm, apices acute to obtuse. Ray corollas rose-pink to purple, laminae oblong-oblanceolate, 5-15 mm, apices obtusely 3-lobed. Disc corollas 5-6 mm. Cypselae 12-35 mm, glabrous or scabridulous proximally, setose distally; pappi of 2-3 widely divergent to reflexed awns 3-5 mm. 2n = 48. Flowering summer-fall. Disturbed sites; 0-10 m; introduced; Fla.; Mexico; West Indies; Central America; South America; also introduced in Asia, Pacific Islands. Within the flora area, Cosmos caudatus is found only in the Florida Keys.