Rudbeckia lacinata Cut leaf Coneflower. A sunflower-like perennial, green-head coneflower’s branched, leafy stalk grows 3-12 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.