Helianthus petiolaris (Prairie Sunflower)
Asteraceae (Sunflower)
Helianthus petiolaris grows on sandy soils in meadows and along roadsides on the plains. It has a bushy growth habit with numerous flower heads about 2-inches in diameter. Leaves are triangular. Phyllaries are lanceolate. Plant height is 2 to 4 feet.

Compare to Helianthus annuus, which grows in similar habitats. H. annuus has broader leaves and broader phyllaries. H. annuus and H. petiolaris can hybridize.

Vegetation zone:  Plains
Time of bloom:  June - September
Origin:  Native
Eastern Colorado Wildflowers