Collection of Helianthus porteri, An Endemic Sunflower of Granite Outcrops in the Southeastern United States.

The genus Helianthus comprises 51 species, 14 annual and 37 perennial, all native to North America. The narrow genetic base of cultivated sunflower has been broadened by the infusion of genes from the wild species, which have provided a continued source of desirable agronomic traits. Confederate daisy, or Porter’s Golden-Eye, Helianthus porteri (A. Gray) Pruski, formerly known as Viguiera porteri (A. Gray) S.F. Blake, is an annual sunflower that was recently transferred to the genus Helianthus. It occurs in and around granite outcroppings in the Piedmont regions of North and South Carolina, Alabama, and Georgia. Unfortunately, the achenes collected from an original population of this species over 30 years ago have not been able to be regenerated, and consequently are not available for research. The objective of this study was to collect achenes from as many Helianthus porteri populations as possible for the USDA-ARS wild sunflower germplasm collection. The exploration covered 1865 miles in the states of Georgia, North and South Carolina, and Alabama during October, 2003. Eight populations were collected from Georgia and North Carolina with population size varying from 500 to 2000 plants. The populations collected significantly increased the number present in the wild sunflower germplasm collection housed at the USDA-ARS North Central Regional Plant Introduction Station, Ames, IA. The achenes collected during this exploration are the first available for almost 30 years for researchers interested in studying this species. It also assures their preservation in the genebank for future use.