Robinia L. (Fabaceae) is a genus of trees and small shrubs native to North America, with several species that are of conservation concern within the Southern Appalachians. The genus has been re-circumscribed utilizing morphologically based taxonomic treatments several times in the last century, though no molecular study has focused solely on the genus. Two taxa within Robinia, both narrowly endemic to the Southern Appalachians, have variously been treated as species or varieties: Robinia viscosa and Robinia hartwigii. I studied the phylogenetic relationships of these species in the context of other members of the genus in the Southern Appalachians utilizing a robust Restriction Site Associated Sequencing (RAD-Seq) dataset. In addition, I will examine the commonly held hypothesis that Robinia hartwigii is a species of hybrid origin. Results from several phylogenetic computational methods were mixed, indicating a potential recent divergence of these taxa, though several support the recognition of Robinia hartwigii at the species level and cast doubt on a hybrid origin of the species.