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.
FNA 2006, Kearney and Peebles 1969
Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Annuals 30-50 cm tall, with greenish unbranched or sparingly branched stems, becoming purplish or yellowish, strigose. Leaves: Opposite, ovate to elliptic or broadly lanceolate blades, 3-5 nerved, 25-70 cm long by 8-35 mm wide, scabrellous. Flowers: On peduncles 10-50 mm long, with narrowly to broadly campanulate involucres, phyllaries obovate to oblong, becoming scarious, glabrous with rounded apices, usually entire to erose, sometimes ciliate; paleae red to purple or yellow with obtuse tips, erose or subentire; ray florets 6-15, usually scarlet red or maroon, linear to spatulate in shape 8-35 mm; disc florets 12-50, corollas yellow 5-6 mm, with 1 mm lobes. Fruits: Cypselae 7-10 mm long, 3-angled in ray flowers or compressed in the disc flowers, ribbed and ciliate with pappi of 1 stout awn 4-6 mm long. Ecology: Found on rocky soils, often calcareous, from 4,000-5,500 ft (1219-1676 m); flowers in summer to fall. Notes: In flower the distinctive red flower is a dead give away. The stems can be decumbent and are deceiving, but the ribbed leaves help when flowers are not present. Ethnobotany: Unknown Etymology: Zinnia is named for Johan G. Zinn (1729-1759) a German botanist, while peruviana means of or from Peru. Synonyms: Crassina multiflora, Zinnia multiflora, Zinnia pauciflora Editor: SBuckley, 2010