Plains sunflower

Helianthus petiolaris, the plains sunflower, is an annual herbaceous species of the Asteraceae family native to central and western North America, particularly the Great Plains and adjacent arid regions. Plants typically reach 30 to 200 cm in height, with slender, branched stems that are often roughly hairy. The leaves are mostly alternate, long-petioled (giving the species its epithet), narrowly ovate to lanceolate, with entire or shallowly toothed margins and a rough-textured surface. Flower heads are radiate, 4 to 8 cm across, with bright yellow ray florets surrounding a dark brown to purplish disk; the receptacle bears pale, often whitish chaffy scales tipped with white hairs that distinguish it from common sunflower. Achenes are small, mottled, and shed at maturity. It grows in sandy soils, dunes, prairies, and disturbed roadsides, flowering from summer into autumn.