The Medicinal Plant Garden

of Birmingham-Southern College

  • Rudbeckia fulgida, hirta, and lacinata
  • Rudbeckia fulgida, hirta, and lacinata
  • Rudbeckia fulgida, hirta, and lacinata

Common Name

Black-eyed Susan, Orange coneflower (fulgida), Brown-eyed Susan (hirta), cut-leaf coneflower (lacinata)

Related Species

Rudbeckia fulgida, hirta, and laciniata are three of many closely related species.

Geographic Distribution and Habitat

Rudbeckia is distributed over most of the United States and parts of Canada. Their native habitat is open woods, meadows, and pastures (Wildflower Database).


R. fulgida is a perennial. Flowers have brown centers and radiating yellow-orange petals that curve slightly downward with teeth at their apical ends. The flower heads are 2-3 inches in diameter. The stems are scattered and 1-3 feet tall with oblong leaves covered with bristly hairs. (Wildflower Database; USDA). R. hirta is an annual to short-lived perennial with characteristics very similar to R. fulgida, but its flowers have a dark brown or brown-maroon center and ‘hairy’ stems. R. laciniata is a perennial with bright golden-yellow flowers that bend backward and cone-shaped green centers that become brownish as they mature. The flower heads are 3-4 inches in diameter. The stems grow 3-12 feet tall with pinnate leaves (Wildflower Database).

Portion of the Plant Used

Various portions of the plant have been used (Moerman, 1998).

Traditional Uses

Rudbeckia were used by early North American Settlers as a diuretic and as a stimulant. Dried plant leaves were usually consumed in the form of a tea. It is also believed that the Potawatomi Indians made tea from the roots, which had immunostimulating properties that relieve symptoms of the common cold (Moerman, 1998). There have been records of different Native American tribes using the plant to aid in the treatment of dropsy, worms, snakebites, and earaches (Moerman, 1998). Cherokee tribes used coneflowers to relieve the discomfort of many gynecological and venereal issues (Hamel and Chiltoskey, 1975).


Recent research on the Black-eyed Susan has been primarily concerned with the polysaccharides and aqueous ethanol extracts of the root of the plant. Experimentation determining the value of the antioxidant properties of the polysaccharides in the root has examined the their ability to inhibit peroxidation of soyabean lecithin liposomes by OH radicals (Kardošová and Machová, 2006). Studies focused on the ethanol extracts of the root have indicated immune-stimulating properties of through the observation of increased activity of phagocytes and the metabolic activity of macrophages, as well as through the increased bacterial activity of microphages on E. Coli cells (Kardošová et al., 1997). Experimentation continues to examine the structural characterization of the active ingredients of the root said to offer antitussive and anti-inflammatory abilities (Capek and Kardošová, 2001).

Side Effects, Interactions, and Contraindications

There have been some reports of the Black-eyed Susan causing skin irritation in humans, and the plant is known to be poisonous to cattle and horses (Perry, 1997).