Publication: Sp. Pl. 2: 904. 1753.
Origin: Native and introduced populations in Washington
selected vouchers: WTU
Notes: FNA21: "Helianthus annuus is widely distributed, including weedy, cultivated, and escaped plants. It is the only native North American species to become a major agronomic crop. Despite its considerable variability, attempts have failed to produce a widely adopted infraspecific system of classification. Forms with red-colored ray laminae, known from cultivation and occasionally seen escaped, trace their ancestry to a single original mutant plant. It hybridizes with many of the other annual species."