may enhance genetic drift. Significant variations have been observed with regard to genotype and chemotype of various beach vitex samples collected from across China. Genotypic and chemotypic variations were closely associated. Large genetic variation between populations was observed with lower variation within populations, and plants within 20 m of each other were closely related. It was believed that differentiation of separated populations might be the cause of variations between populations. Medicinal uses Vitex rotundifolia has many medicinal uses. These uses generally parallel those of Vitex agnus-castus. Environmental concerns In areas where it has been introduced outside of its native range, V. rotundifolia has proven to be an invasive species. This plant dominates dune ecosystems leading to a reduction in the prevalence of native species. Native species exclusion is of particular concern because some of the species that share a niche with V. rotundifolia, such as sea beach amaranth (Amaranthus pumilus Rafinesque), are presently listed as threatened. Vitex rotundifolia fruits have been shown to transfer cuticular alkanes to the sand substrate. This results in intense sand hydrophobicity that persists in the soil for many years. This hydrophobicity might negatively impact dune recovery or serve as a means for limiting growth of native plant species. Sea turtle conservation groups have publicized concerns that dense V. rotundifolia growth may prevent sea turtles from reaching acceptable nesting sites. These same organizations believe that V. rotundifolia may limit the ability of baby turtles to reach the ocean after they hatch. A recent USA Today article mentioned these concerns as part of an effort to raise awareness of V. rotundifolia, and has at least one review article. However, these concerns have not been validated scientifically. Several sea turtle species nest along the coasts of the Carolinas. These include the endangered loggerhead turtle (Caretta caretta), the endangered green turtle (Chelonia mydas), and the critically endangered Kemp's ridley (Lepidochelys kempii). If scientific evidence is found to support claims that V. rotundifolia harms sea turtles, this threat would constitute a substantial environmental issue. Beach vitex emits large amounts of methyl chloride from its leaves. V. rotundifolia was one of the six highest emitting species of 33 possessing this characteristic. A total of 187 species were examined. Methyl chloride is produced naturally, but may be responsible for a substantial portion of the negative impacts on the stratospheric ozone layer. Legislation In light of the invasive characteristics of V. rotundifolia, it