Rudbeckia Hirta

Black-eyed Susan, Brown Betty, Gloriosa Daisy, Brown Daisy


The Black-eyed Susan is a perennial plant. Its green stem grows to be 1-2 ft tall and is covered with small bristly hairs. The leaves are oval shaped and can grow up to 7 in long1.similarly to the stem are also covered in small hairs7. The characteristic feature of this plant is its bright yellow flower. The flower is usually 2-3 in wide containing 8-21 petals and has a dark brown/black colored center1

The black-eyed susan blooms between June and October1. These plants require medium amounts of water and a range of growing conditions. Black-eyed Susans can be propagated easily from seeds. Put the seed in loose topsoil with ¼ to ½ in soil or mulch on top. The plants have a high drought tolerance in general and can grow easily in areas of high sun, partial sun, and even some shady regions. Because of the variety of tolerable conditions, black-eyed susans can become an aggressive and invasive plant if they are not given enough competition where they are planted7


The two main active constituents in the black-eyed susan are sesquiterpene lactones and pulchelin. Sesquiterpene lactones have been studied to be responsible for certain anti-microbial activity2.  Pulchelin is a particular type of sesquiterpene lactone that is isolated from Black-eyed Susan plants in particular. This compound has been shown to be the active member in anti-worm activity, anti-inflammatory responses, and antibacterial properties. This lactone is taken directly from the root of the plant and certain labs have tried to replicate the structure formation in cultures, however the amounts produced have been relatively low in comparison to naturally occurring structures3

Fun Fact:

The scientific name of the Black-eyed Susan was named for Olaf Rudbeck who was the Botany professor of Linnaeus, the man who developed the binomial nomenclature system. Also. The Black-eyed Susan is the official state flower of Maryland5


Native American Tribes first used the Black-eyed Susan medicinally. The tribe Ojibwa, or Chippewa, treated snake bites by making the plant into an external wash. Additionally, they turned it into an infusion that could be used to treat both colds and worms. The Menominee and Potawatomi tribes utilized the root’s diuretic properties in the form of a tea. Also the root juices were used to treat earaches1


Most commonly the roots of the Black-eyed Susan are made into a warm decoction that can then be used to wash both sores and swelling. The seeds are poisonous and are therefore not used in any type of medicinal treatment4. Also, strain any tea that is made to get rid of the hairs that could cause irritation3. This plant is not used as much medicinally nowadays, but is rather more popular for its visual appeal. They are commonly found in gardens and bouquets for their vibrant color. Additionally, they attract both birds and butterflies. The Black-eyed Susan is the larval host for two particular types of butterflies-the Bordered Patch and Gorgone Checkerspot7


Decoction- take the roots of Black-eyed Susan plant and simmer or boil the herbs. This should then be reduced to about 1-4 of the original volume and strained before used. Or one can add between 1-2 teaspoons of the dried herb per 2 cups of water. For this tea one can drink 1-3 cups per day1

Contraindications/Interactions/Adverse Reactions:


References Cited:

1. Church, B. (n.d.). Medicinal Plants, Trees, and Shrubs of Appalachia. Retrieved March 13, 2012, from     wplants.pdf.

2. Rodriguez, E., Towers, G., and Mitchell, J. (2001). Biological activities of sesquiterpene lactones. Phytochemistry 15:1573-1580. Retrieved March 13, 2012, from

3. Luczkiewicz, M., Zarate, R., Dembinska-Migas, W., Migas, P., and Verpoorte, R. (2002). Production of pulchelin E in hairy roots, callus and suspension cultures of Rudbeckia hirta L. Plant Science 163:91-100. Retrieved March 13, 2012, from http://discover-decouvrir.cisti-icist.nrc-

4. Ho, A. (2010). Medicinal Herbs: Black-eyed Susan. Retrieved March 13, 2012, from  susan.html.

5. Maryland State Archives. (2010). Maryland State Flower-Black-eyed Susan.  Retrieved March 13, 2012, from tml.

6. Wildseed Farms. (n.d.). Black-Eyed Susan. Retrieved March 13, 2012, from    

7. Lady Bird Johnson Wildflower Center. (2012). Rudbeckia hirta L. Retrieved March 13, 2012, from   

8. USDA (n.d.). Rudbeckia hirta L. var. pulcherrima Farw. Blackeyed Susan. Retrieved March 19, 2012, from