This award will support collaborative research in systematic biology between Dr. Delbert Wiens, University of Utah and Dr. Roger Polhill, Royal Botanic Gardens, Kew, England. Specifically, Dr. Wiens and Polhill plan to complete a book-length manuscript on the classification and biological aspects of the African representatives of the plant families Loranthaceae and Viscaeae. These families are commonly known as mistletoes and have a worldwide, primarily tropical, distribution. Both families exhibit relatively high species diversity in Africa, with a combined total of about 250 species. This project is a culmination of approximately five years of collaborative study between the two investigators and has encompassed field studies over much of the African continent. The result of this study should be a significant contribution to the study of biodiversity of the African flora. The African members of these families have not been studied in detail since the turn of the century.