Rudbeckia hirta

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Rudbeckia hirta
Black eyed susan 20040717 110754 2.1474.jpg
Rudbeckia hirta flowerhead
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Asteraceae
Genus: Rudbeckia
Species: R. hirta
Binomial name
Rudbeckia hirta

Rudbeckia hirta, commonly called black-eyed Susan, is a species of flowering plant in the family Asteraceae, native to the Eastern and Central United States. It is one of a number of plants with the common name black-eyed Susan. Other common names for this plant include: brown-eyed Susan, brown Betty, gloriosa daisy, golden Jerusalem,[1][2] Poorland daisy, yellow daisy, and yellow ox-eye daisy.

It is the state flower of Maryland.[3]

The plant also is a traditional Native American medicinal herb in several tribal nations;[4] believed in those cultures to be a remedy, among other things, for colds, flu, infection, swelling and (topically, by poultice) for snake bite (although not all parts of the plant are edible)[5]

Parts of the plant have nutritional value. Other parts are not edible.


It is an upright annual (sometimes biennial or perennial) growing 30–100 cm (12–39 in) tall by 30–45 cm (12–18 in) wide. It has alternate, mostly basal leaves 10–18 cm long, covered by coarse hair, with stout branching stems and daisy-like, composite flowers appearing in late summer and early autumn. In the species, the flowers are up to 10 cm (4 in) in diameter, with yellow ray-florets circling conspicuous brown or black, dome-shaped disc-florets.[6] However, extensive breeding has produced a range of sizes and colours, including oranges, reds and browns.[7]


The genus name honors Olaus Rudbeck, who was a professor of botany at the University of Uppsala in Sweden and was one of Linnaeus's teachers. The specific epithet refers to the trichomes (hairs) occurring on leaves and stems.[8]


There are four varieties:

  • Rudbeckia hirta var. angustifolia. Southeastern United States (South Carolina to Texas).
  • Rudbeckia hirta var. floridana. Florida, endemic.
  • Rudbeckia hirta var. hirta. Northeastern United States (Maine to Alabama).
  • Rudbeckia hirta var. pulcherrima. Widespread in most of North America (Newfoundland to British Columbia, south to Alabama and New Mexico; naturalized Washington to California).


R. hirta is widely cultivated in parks and gardens, for summer bedding schemes, borders, containers, wildflower gardens, prairie-style plantings and cut flowers. Numerous cultivars have been developed, of which 'Indian Summer'[9] and 'Toto'[10] have gained the Royal Horticultural Society's Award of Garden Merit. Other popular cultivars include 'Double Gold' and 'Marmalade'.

Gloriosa daisies are tetraploid cultivars having much larger flowers than the species, often doubled or with contrasting markings on the petals. They were first bred by Alfred Blakeslee of Smith College by applying colchicine to R. hirta seeds; Blakeslee's stock was further developed by W. Atlee Burpee and introduced to commerce at the 1957 Philadelphia Flower Show.[11] Gloriosa daisies are generally treated as annuals or short-lived perennials and are typically grown from seed, though there are some named cultivars.

Symbolism and uses[edit]

Maryland state flower[edit]

This variety is the Maryland state flower[3] and is widely planted in gardens and used in ceremonies there. It also grows wild throughout much of the state.[3]
  • The black-eyed Susan was designated the state flower of Maryland in 1918.[3][12] In this capacity it is used in gardens and ceremonies to celebrate, memorialize and show affection for the state of Maryland and its people.
  • The Preakness Stakes in Baltimore, Maryland has been termed "The Run for the Black-Eyed Susans" because a blanket of chrysanthemums, decorated to look like black-eyed Susans, is traditionally placed around the winner's neck (actual black-eyed Susans are not in season during the Preakness).

Symbol of Justice[edit]

  • The black-eyed Susan which also traditionally symbolizes “Justice” makes a very nice cut-flower with a vase life up to 10 days.[13]

Butterfly attractant for enhancing gardens[edit]

  • Butterflies are attracted to Rudbeckia hirta when planted in large color-masses, creating a beautiful spectacle.[14]

Traditional Native American medicinal uses[edit]

  • The roots but not the seedheads of Rudbeckia hirta can be used much like the related Echinacea purpurea to boost immunity and fight colds, flu and infections.
  • It is also an astringent when used in a warm infusion as a wash for sores and swellings.[citation needed]
  • The Ojibwa people used it as a poultice for snake bites[15] and to make an infusion for treating colds and worms in children.
  • The plant is also diuretic and was used by the Menominee and Potawatomi peoples.[16][17]
  • Juice from the roots has been used as drops for earaches.[18]

Nutritional parts[edit]

  • Certain parts of the plant contains anthocyanins[19] a class of antioxidant with several known health benefits.


  • As with any wild plant, it is usually recommended to research carefully before consuming as not all parts of the plant may be edible and to avoid mis-identification with other plants that may look similar to the Black eyed Susan.
  • It is widely recommended to always consult one's Doctor before taking any medicinal herb.
  • With any herb approved by a Doctor for use, it is widely agreed that recommended dosages and preparation procedures should always be followed.
  • The species is also known to be toxic to cats when ingested. [20]



  1. ^ Dolgopolov, Y. (2004). A collection of confusable phrases: False 'friends' and 'enemies' in idioms and collocations. Coral Springs, FL: Llumina Press
  2. ^
  3. ^ a b c d "MARYLAND AT A GLANCE: STATE SYMBOLS, Maryland State Flower - Black-Eyed Susan", Maryland State Archives, Maryland Manual Online,
  4. ^ Moerman. D, "Native American Ethnobotany", Timber Press. Oregon. 1998 ISBN 0-88192-453-9
  5. ^ Moerman. D, "Native American Ethnobotany", Timber Press. Oregon. 1998 ISBN 0-88192-453-9
  6. ^ Floridata: Rudbeckia hirta.
  7. ^ RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964. 
  8. ^ Andy's Northern Ontario Wildflowers: Native Meadow Wildflowers. Black-eyed Susan.
  9. ^ "RHS Plant Selector - Rudbeckia hirta 'Indian Summer'". Retrieved 2 June 2013. 
  10. ^ "RHS Plant Selector - Rudbeckia hirta 'Toto'". Retrieved 2 June 2013. 
  11. ^ Lacy, Allen (July 21, 1988). "Gloriosa, the Eliza Doolittle of Daisies". New York Times. Retrieved 2013-10-22. 
  12. ^ "Fiscal and Policy Notes (HB 345)" (PDF). Department of Legislative Services - Maryland General Assembly. 2010. Retrieved 2010-03-13. 
  13. ^ "Black Eyes Susan Wildflower". 
  14. ^ Schillo, Rebecca (2011). Cummings, Nina, ed. "Native Landscaping Takes Root in Chicago". In The Field: 13. 
  15. ^ Black-Eyed Susan
  16. ^ Herbs
  17. ^ Rudbeckia hirta
  18. ^ Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998 ISBN 0-88192-453-9
  19. ^ Cat.Inist
  20. ^ "List of plants toxic to cats".