Rudbeckia fulgida ea


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


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


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).


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


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).


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).


Capek, P., and A. Kardošová. Structural Characterization of an Acidic Heteropolysaccharide from Rudbeckia Fulgida, Var. Sullivantii (Boynton Et Beadle). Chem. Pap. 55.5 (2001): 311-18.

Hamel, Paul B., and Mary Ulmer Chiltoskey. Cherokee Plants and Their Uses: A 400 Year History. Sylva, NC: Herald Pub., Comp. 1975.

Kardošová, A., D. KOŠŤÁLOVÁ,, P. Capek, V. PÄTOPRSTÝ,, and S. FRAŇ0VÁ. “Water-Extractable Polysaccharide Complex of Rudbeckia fulgida Var. sullivantii (Boynton Et Beadle) Possesses Antitussive Activity.” Chem. Pap. 51.1 (1997): 52-59

Kardošová, A., and E. Machová. “Antioxidant Activity of Medicinal Plant Polysaccharides.” Fitoterapia 77 (2006): 367-73.

Kingsbury, J.M. (1964). Poisonous Plants of the United States and Canada. Prentice-Hall Inc., Englewood Cliffs, N.J.

Lee, S.Y., Y.J. Shin, S.U. Choi and K.R. Lee. A new flavonol glycoside from the aerial part of Rudbeckia laciniata. Arch Pharm Res. 2014 Jul;37(7):834-8.

Michael, B.R., S.R. Gedara, M.M. Amer, L. Stevenson and A.F. Ahmed. A new highly oxygenated pseudoguaianolide with 5-LOX inhibitory activity from Rudbeckia hirta L. flowers. Nat. Prod. Res. 2013, 27, 2281-5.

Moerman, Daniel E. (1998) Native American Ethnobotany. Portland, Or.: Timber Press

Perry, Leonard P. Potentially Harmful Perennials. University of Vermont Extension System Department of Plant and Soil Science, 1997.

Researched and written by BSC Student Kelsey Moore (2013)


Title/abstract search for Rudbeckia fulgida at PubMed

Title/abstract search for Rudbeckia hirta at PubMed

Title/abstract search for Rudbeckia laciniata at PubMed

Title/abstract search for Rudbeckia spp. at PubMed

University of Texas Austin, Wildflower Center

USDA NRCS Plant Database R. fulgida

USDA NRCS Plant Database R. hirta

USDA NRCS Plan Database R. laciniata

Pharmazie. 2000 Jan;55(1):65-8.

Antitussive activity of a glucuronoxylan from Rudbeckia fulgida compared to the potency of two polysaccharide complexes from the same herb. Nosál'ová G1, Kardosová A, Franová S.

An alkali-extracted low-molecular glucuronoxylan and two water-extractable polysaccharide complexes isolated from various parts of Rudbeckia fulgida were tested for antitussive activity on mechanically induced cough in nonanaesthetized cats. Glucuronoxylan consisted of a (1-->4)-linked beta-D-xylopyranosyl backbone with about 18% of 4-0-methyl-D-glucuronic acid attached to 0-2 of the chain xylose residues. The polysaccharide complexes differed from each the other regarding the in qualitative and quantitative composition of the sugar components. It was found that peroral administration of all the compounds led to a significant suppression of the cough reflex without negative influence on expectoration. Glucuronoxylan and the complex from the aerial parts of the herb exhibited much higher antitussive activity than the complex from the roots which did not contain any uronic acid component. Their activity (48.2% and 46.5%, respectively) highly surpassed the activity of the complex from the roots (23.5%) as well as that of the peripherally acting drugs dropropizine (28.3%) and prenoxdiazine (24.7%).