Helianthus pauciflorus--Showy Sunflower

Showy Sunflower (sometimes called Prairie Sunflower) can grow up to 5 or 6 feet tall and prefer dry, sunny conditions. They spread through rhizomes and can form dense colonies.  In the landscape, they're best used where they can spread, but can also be used as a hedge along a fence or as a backdrop to shorter plants.