Sunday, July 15, 2012

Plant Profile: Rudbeckia hirta, Black-eyed Susan

By Shannon Sardisco and Shannon Tapscott

This post is one of a series from professor Nisse Goldberg's Botany students at Jacksonville University.

Figure 1. Black-eyed Susan, Rudbeckia hirta.
Photo credit: Keith Bradley.
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Asterales
Family: Asteraceae
Genus: Rudbeckia
Specific epithet: hirta

Rudbeckia hirta, or black-eyed or brown-eyed Susan, is one of nine species of Rudbeckia native to Florida. As with many of the Asteraceae, the flowers are found on a head with both ray and disk flowers (Figure 1).  The ray flowers are golden yellow and as the common name suggests, the disk flowers are dark brown.  Black-eyed Susan blooms during the months of July through October, offering nectar to pollinators such as butterflies and bees. The bristly stems (Figure 1) are 1-2 feet tall, with oval leaves.
Figure 2. R. hirta seeds. Photo credit: ARS Systematic
Botany and Mycology Laboratory

Black-eyed Susans are not only grown for their beautiful flowers. Their nectar and seeds (Figure 2) attract wildlife, and their leaves can serve as a host plant for some butterfly larvae. Rudbeckia hirta is a relatively low-maintenance, sun-loving, drought-tolerant native. Interestingly, the plant has been used to treat colds, snakebites and even earaches!

Interested in growing your own? Consider purchasing from a vendor of the Florida Association of Native Nurseries:

United States Department of Agriculture. (2012). Plant Database,
The University of Texas at Austin. (2012). Native Plant Database,
Florida Friendly Landscaping. (2012). The Smart Way to Grow,
Lady Bird Johnson Wildflower Center,
Wunderlin, R. P., and B. F. Hansen. 2008. Atlas of Florida Vascular Plants ([S. M. Landry and K. N. Campbell (application development), Florida Center for Community Design and Research.] Institute for Systematic Botany, University of South Florida, Tampa.

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