Developing New Morphological, Geographic, and Molecular Tools to Circumscribe Hexastylis naniflora

Hexastylis Rafinesque is a genus of 11 species that is broken down into three groups. The Hexastylis Heterophylla subgroup contains three closely related species: H. heterophylla Small, H. minor Blomquist, and H. naniflora Blomquist. Hexastylis naniflora is a perennial evergreen herb, native to the southeastern United States. Hexastylis naniflora was listed by the US Fish and Wildlife Service as federally ‘threatened’ in 1989 and continues to face threats associated with habitat loss and global climate change. Due to increased monitoring, the number of populations recognized by USFWS has increased four-fold, resulting in the consideration to de-list this species. Monitoring and identification of H. naniflora have been problematic due to the overlap in flower and leaf morphology with other members of the subgroup. Habitat variables were used to generate a site suitability model to predict quality of habitat for H. naniflora. These findings can be used to discover new populations of H. naniflora and locate the best habitat for transplanting projects. Morphological analyses of leaf shape, leaf venation, leaf tip, and calyx ridge height have generated new markers to distinguish species of the Hexastylis Heterophylla subgroup. Lastly, 15 primer pairs have been developed that amplify microsatellite loci across all three species.