Prairie Sunflower

Prairie Sunflower

Helianthus petiolaris Nutt.

Asteraceae (Sunflower Family)

▲ ▼ young plants

▲ ▼ mature flowering plants

leaves and flower buds ▲

▲ flower closer view

Helianthus petiolaris Nutt., Prairie Sunflower: (Bayer Code: HELPE; US Code HEPE)

U.S. native summer annual, 1-4 feet tall, with green to brownish-purple stems; stems are rough-hairy, and plants branch from the base
Leaves are opposite, triangular to lanceolate, rough-textured, with long petioles; leaves have a few teeth or smooth margins; three main leaf veins arise from the petiole
Head inflorescences are 1.5-3 inches across, with 10-30 ray florets (“petals") that are puckered where they join the head, and center of 50-100 reddish-brown disk florets
Stalks supporting the heads (peduncles) can be up to 16 inches long
Bracts below the inflorescence are in several rows, lanceolate with elongated pointed tips, rough-textured, with hairs on margins; bracts stand out from the base of the inflorescence
Flowering from mid-summer to mid-autumn
Found in cultivated fields, right-of-ways, prairies, pastures; more common in disturbed sites; tolerant of sandy soils; more common in western plains states
Appears quite similar to Annual Sunflower (Helianthus annuus), except annual sunflower has larger flowers and leaves, leaves are more broad, and flower stalks (peduncles) tend to be shorter