Helianthus petiolaris

About

Helianthus petiolaris is a North American plant species in the family Asteraceae, commonly known as the prairie sunflower or lesser sunflower. Naturalist and botanist Thomas Nuttall was the first to describe the prairie sunflower in 1821. The word petiolaris in Latin means “having a petiole”. The species originated in Western United States, but has since expanded east. The prairie sunflower is sometimes considered a weed.

Summary from Wikipedia