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.
Classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Asterales
Family: Asteraceae
Genus: Rudbeckia
Specific epithet: hirta

Description
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: http://www.floridanativenurseries.org/plants/detail/rudbeckia-hirta

References
United States Department of Agriculture. (2012). Plant Database, http://plants.usda.gov/java/profile?symbol=ruhi2
The University of Texas at Austin. (2012). Native Plant Database, www.wildflower.org/plants/result.php?id_plant=RUHI2
Florida Friendly Landscaping. (2012). The Smart Way to Grow, http://www.floridayards.org/fyplants/plantquery.php
Lady Bird Johnson Wildflower Center, http://www.wildflower.org/plants/result.php?id_plant=RUHI2
Wunderlin, R. P., and B. F. Hansen. 2008. Atlas of Florida Vascular Plants (http://www.florida.plantatlas.usf.edu/).[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.

Image Sources

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