The species of North American Vitus are economically important as rootstocks for the commercial grape (Vitus vinifera L.) and as a germ source for production of new hybrid cultivars. For native species of grapes to be most effectively used in the development of new cultivated grapes, their genetic diversity and relationships must be adequately assessed. Chemical analyses of leaf pigments (flavonoids) and anatomical characteristics will be used to infer relationships among species in two genera of Vitus from eastern North America. Results from this analysis should help determine the most likely evolutionary history of the species and produce a classification that will prove useful from an agricultural and systematic standpoint.
