Common Sunflower blooms from February to October, nearly all year. It is similar in appearance to Slender Sunflower, but larger and more stout.

The large radiant flowers punctuate the tops of long erect stems, with yellow ray flowers and brownish purple disk flowers, overall varying from 2 to 6 inches in diameter. The leaves are oval shaped with sawtoothed edges and can be as big as 10 inches in diameter. Flowers have a sticky feel, while leaves and stems are hairy and rough.

The giant sunflower you normally see in gardens is a relative of this native. The genus name Helianthus is from two Greek words meaning "sun" and "flower". The species name annus means "annual". Native people used not only the seeds as food, but cultivated fibers from the stems and made a dye from the flowers.