Houstonia montana (Chickering) Small (1933) appears to be morphologically and genetically distinct from H. purpurea L. (Rubiaceae). Houstonia montana was collected from the population on Roan Mountain, North Carolina, while H. purpturea was collected from populations on Roan and Bald Mountains, North Carolina. Statistically significant morphological differences were observed between the populations of H. montana and H. purpurea. Experimental crosses between H. montana and H. purpurea suggest that a definite breeding barrier exists between these taxa. Therefore, H. montana should be considered a distinct species, not an ecological variety or morphological variation of H. purpurea.