Giant Whorled Sunflower


Committee Members:

Patrick Thompson (chair): Auburn University Davis Arboretum
Wayne Barger: Alabama Department of Conservation and Natural Resources
Soozi Pline: Huntsville Botanical Gardens
Contact Point:
Patrick Thompson, Davis Arboretum. 101 Rouse Life Sciences Building
Auburn University AL, 36849-5407 (334) 332.0283

This species was first discovered in Tennessee in 1892, but was thought to have been extinct until 1994 when it was rediscovered in Georgia. Subsequent efforts have located the whorled sunflower in five distinct populations (TN, GA, and AL). Helianthus verticillatus (Giant Whorled Sunflower) has been listed as a Federal Endangered Species since 2014. Population analysis performed by Dr. Jennifer Ellis Mandel in 2006-2007, as part of her dissertation work at Vanderbilt University, revealed that the total worldwide number of genetically distinct individuals may only range between 300-400 plants.

In 2008, the two reported Helianthus verticillatus sites in Alabama were visited to assess the status of this species in our state. One population appeared to have been extirpated, while the other population had approximately 30 mature individuals. Work to improve the site and partner with the Cherokee County Highway Department began immediately. “Do Not Mow” signs were posted and encroaching woody stems were cut in early 2009. In the Fall of 2009, population estimates had increased to near 10-fold the 2008 the number of mature stems, to approximately 300 stems. The roadside plants are still in an unstable location, suffering from encroaching woody plants, and have been negatively impacted by drought and mowing issues.

Short-term Goals:

1. Encourage stability of existing AL populations through site clean ups

2. Collect divisions from both AL populations for propagation

Long-term Goals:

1. Avoid loss of genetic diversity by advocating for protected sites, and make safeguarding available for AL populations

2. Augment existing populations

3. Manage existing sites for long-term viability of the species


1. Protective signage has reduced damage at roadside population

2. Preliminary success in sexual and vegetative propagation

3. Six rhizomatous divisions (removed from the Cherokee County, AL site in early May 2010) were cultivated for seed.

4. Hundreds of seedlings grown out by gardens and individuals in AL and GA

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