Helianthus annuus L., Sp. Pl. 2: 904 (1753).
Dried heads of sunflowers are sometimes encountered in potpourri. Involucral bracts are in two to several series, the other often leafy at tips. The ray-florets are neutral, yellow; disk-florets are bisexual and fertile, yellow, brown, or purplish. The receptacle is flat or convex, with chaffy bracts. While cultivated sunflowers may bear heads to 35 cm across, ones chosen for potpourri are smaller, about 2-6 cm in diameter, and sometimes bleached.
Helianthus annuus is native to North America but widely cultivated elsewhere.
Asteraceae (alt. Compositae)