Both Blomquist and Gaddy recognized a group of eight Hexastylis (commonly known as “Wild Gingers” or “Little Brown Jugs”) that are referred to as the Virginica Group. This group was further subdivided into the three Subgroups: Virginica, Shuttleworthii, and Heterophylla. Three species have been recognized in the Heterophylla complex. Field biologists have generally recognized considerable morphological overlap occurs in this group. The three species that are placed in the Heterophylla complex are Hexastylis naniflora, H. heterophylla and H. minor. Hexastylis naniflora is a federally threatened species that is found in the rapidly growing area of the western Piedmont of North and South Carolina. The range of H. naniflora is restricted by soil type, biogeography, and ecology. Herbarium specimens were borrowed from 17 herbaria and these 693 specimens were used to generate distribution maps for the three species in the H. heterophylla complex. Elemental occurrence data were obtained from the North Carolina Natural Heritage Program and the South Carolina Heritage Trust Program to augment the distribution map for H. naniflora. Based upon these maps, field investigations were conducted across the range of the three species in the complex. We conducted ecological, morphological, micromorphological, soil, pollen, and molecular analyses of the H. heterophylla complex. Using ecological and biogeographical information obtained from our study, we located 31 new populations of H. naniflora; one of the new populations was found to be unique to the Yadkin River drainage. This effort brings the total known populations of H. naniflora to 143. Eighty-five populations of the three species in the H. heterophylla complex were subjected to field investigations. Using Scanning Electron Microscopy (SEM), we found pollen characters that distinguish H. naniflora from other members within the subgroup. In a comparative analysis using Inter Simple Sequence Repeats, we were unable to find banding patterns that could be used to separate H. naniflora from the other members within the complex. Based upon biogeographical, ecological, molecular, morphological, as well as micromorphological work, our results show that H. naniflora Blomquist is a well-defined species, however, Hexastylis minor (Ashe) Blomquist and Hexastylis heterophylla (Ashe) Small exhibit considerable overlap that make species circumscription difficult. Our intraspecific analysis of Hexastylis naniflora was based on analysis of soil, ecology, molecular characters and morphology, where we compared populations in the Broad-Pacolet, Catawba, and Yadkin River drainages. This analysis provides information that can be used in future conservation and management efforts for H. naniflora.
