The species are herbaceous, mostly perennial plants (some annual or biennial) growing to 0.5–3.0 m tall, with simple or branched stems. The leaves are spirally arranged, entire to deeply lobed, and 5–25 cm long. The flowers are produced in daisy-like inflorescences, with yellow or orange florets arranged in a prominent, cone-shaped head; "cone-shaped" because the ray florets tend to point out and down (are decumbent) as the flower head opens.
A large number of species have been proposed within Rudbeckia, but most are now regarded as synonyms of the accepted quite limited list. Several currently accepted species have several accepted varieties. Some of them (for example the black-eyed susan, R. hirta), are popular garden flowers distinguished for their long flowering times. Many cultivars of these species are known. Rudbeckia is one of at least four genera within the flowering plant family Asteraceae whose members are commonly known as coneflowers; the others are Echinacea, Dracopis, and Ratibida. Rudbeckia species are eaten by the caterpillars of some Lepidoptera species including cabbage moths and dot moths.









