Rudbeckia // is a plant genus of 23 species in the family Asteraceae. The species are commonly called coneflowers and black-eyed-susans; all are native to North America and many species are cultivated in gardens for their showy yellow or gold flower heads.
The species are herbaceous, mostly perennial plants (some annual or biennial) growing to 0.5–3 m tall, with simple or branched stems. The leaves are spirally arranged, entire to deeply lobed, 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 limited list given below. Several of these 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. There are many cultivars of these species.
The name was given by Carolus Linnaeus in honor of his teacher at Uppsala University, Professor Olof Rudbeck the Younger (1660-1740), and his father, Professor Olof Rudbeck the Elder (1630-1702), both of whom were botanists. 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.
Formerly placed here
- Echinacea atrorubens (as R. atrorubens)
- Echinacea pallida (as R. pallida)
- Echinacea purpurea (as R. purpurea)
- Helianthus angustifolius (as R. angustifolia)
- Helianthus porteri (as R. porteri)
- Helianthus radula (as R. radula)
- Ratibida columnifera (as R. columnaris or R. columnifera)
- Ratibida tagetes (as R. tagetes) 
Many species are used in prairie restorations and for ornamental use. Used by domestic stock for forage. An abundance of these plants on a rangeland indicates good health.
- Sunset Western Garden Book, 1995:606–607
- "Species Records of Rudbeckia". Germplasm Resources Information Network. United States Department of Agriculture. Retrieved 2010-06-05.
- "Rudbeckia". Integrated Taxonomic Information System. Retrieved 5 June 2010.