Annuals, mostly 30-50(-100) cm. Stems greenish, becoming purplish or yellowish, unbranched or sparingly branched distal to bases, strigose. Leaf blades 3-5-nerved, ovate to elliptic or broadly lanceolate, 25-70 × 8-35 mm, scabrellous. Peduncles 10-50(-70) mm. Involucres narrowly to broadly campanulate, 9-18 × 10-20 mm. Phyllaries obovate to oblong, becoming scarious, glabrous, apices rounded, usually entire or erose, sometimes ciliate. Paleae red to purple or yellow, apices obtuse, erose or subentire. Ray florets 6-15(-21); corollas usually scarlet red or maroon, sometimes yellow, laminae linear to spatulate, 8-25 mm. Disc florets 12-50; corollas yellow, 5-6 mm, lobes ca. 1 mm. Cypselae 7-10 mm, 3-angled (ray) or compressed (disc), ribbed, ciliate; pappi usually of 1 stout awn 4-6 mm (from shoulders of cypselae). 2n = 24. Flowering summer-fall. Rocky roadsides, ravines, calcareous soils; 1200-1600 m; Ariz., Fla., Ga., N.C., S.C.; Mexico; West Indies (Hispaniola); Central America; South America; introduced in Asia (China), South Africa, Australia. Zinnia peruviana is presumably native in southern Arizona and reported as naturalized in southeastern United States.

Plant: Annual forb 20-30 cm Leaves: leaves opposite, lance-ovate, 2-4 cm long, sandpapery Flowers: flower head borne singly at ends of branching stems; ray flowers deep red, conspicuous; phyllaries strongly graduated.