n. 1. Any plant of the genus Rudbeckia; -- so called from the cone-shaped disk of the flower head. They are cultivated for their large usually yellow daisies with prominent central cones. Also, any plant of the related genera Ratibida and Brauneria, the latter usually known as purple coneflower. [ Webster 1913 Suppl. ]

2. any of various perennials of eastern US having thick rough leaves and long-stalked showy flowers with drooping rays and a conelike center. [ WordNet 1.5 ]