Helianthus decapetalus (ten-petaled sunflower)

Ten-petaled sunflower has a star-like bloom -- ten bright yellow petals with either rounded or pointed tips. This sunflower reaches between 1.5 to 5 feet in full to part sun. Plant this in sandy moist soils as it is typically found in moist bottomlands, stream banks, and roadsides. It blooms July through October.