A sunflower-like perennial, Green-head Coneflower’s branched, leafy stalk grows 3-10 ft. tall. The stemmed flowers are at the apex of the stalk. Each flowers is 3-4 in. across, with cone-shaped, greenish-yellow centers and back-tilted golden rays. The center cones elongate and become brownish as the seeds ripen. Attractive leaves are pinnately dissected and emerge early in spring.

Blackeyed Susan (R. hirta), an eastern species introduced many places in the West, has a dark brown or brown-maroon hemispheric disc surrounded by orange-yellow, somewhat drooping rays. The lanceolate leaf blades sometimes have teeth, and there is no crown or ring of scales on the fruit.

Source: https://www.wildflower.org/plants/result.php?id_plant=rula3