Floristics of Piedmont Gabbro Upland Depression Forests in Jasper County, Georgia

Piedmont Gabbro Upland Depression Forests are a globally imperiled (G2) association endemic to a few scattered locations in the Piedmont regions of Georgia and South Carolina. These distinctive communities occur in relatively level uplands over mafic shrink-swell clays, particularly Iredell soils, derived from gabbro bedrock, and the hydrology ranges from seasonally saturated to very dry. These sites support unusual assemblages of plants including species typically associated with wetlands, xeric areas, and the Coastal Plain. A vouchered floristic inventory was conducted of three sites (270 ha; 666 ac) in Oconee National Forest in Jasper County, Georgia. The survey documented 541 vascular plant species (and eight varieties) in 319 genera and 111 families. The 86 exotic species comprise 15.9% of the flora. According to state rankings, five rare plant species occur within the study area, including Quercus oglethorpensis (state-ranked threatened). Herein, we provide an annotated species list and maps, descriptions, and photographs of the study site.