Description from Flora of China
Annuals, perennials, subshrubs, or shrubs. Stems erect, branched. Leaves all or mostly cauline, opposite (proximal) or mostly alternate, petiolate or sessile; blade mostly deltate or pentagonal, sometimes 3- or 5-lobed, often (1 or)3- or 5-veined, both surfaces glabrous, ± hirsute, pilose, soft pubescent, or villous, often gland-dotted, base truncate or auriculate, ultimate margin serrate to crenate. Capitula borne singly; peduncles usually distally dilated, fistulose; involucres campanulate to hemispheric; phyllaries persistent, 2-5-seriate; receptacles hemispheric to convex, paleate. Ray florets 8-30, neuter; corollas yellow or orange. Disk florets bisexual, fertile; corollas yellow, tubes shorter than throats, lobes 5, triangular. Achenes compressed or flattened, often 3- or 4-angled or biconvex, cuneiform in silhouette, sometimes with basal elaiosomes; pappus absent or coroniform, of connate scales, 1 or 2 scales sometimes subulate to aristate. x = 17.
See La Duke, Rhodora 84: 463-522. 1982.
Tithonia rotundifolia (Miller) S. F. Blake is cultivated in China.
About 11 species: Mexico, SW United States; Central America; one species (introduced) in China.