This award will support cooperative research between Dr. Peter Crane of the Field Museum of Natural History and Dr.Andrew Drinnan of the University of Melbourne. The flowering plants comprise the largest group of plants, Angiospermae with approximately 500,000 species. In addition to their sheer diversity, the angiosperms are of great economic importance to humans. Angiosperms are also major elements of many or most terrestrial ecosystems. Understandably, botanists have been interested in developing models and inferences concerning the origin and radiation of this highly significant group. Within the past two decades, techniques such as molecular systematics have become available to permit rigorous scientific inquiry into the problem of the origin of the flowering plants and phylogenetic models of the group. The focus of this research is a detailed study of floral development and morphology in the angiosperm family Buxaceae to clarify homologies and resolve generic level relationships. Utilizing developmental information and other data, the project will critically assess contrasting hypotheses on the phylogenetic position of the Buxaceae. In addition, the broader implications for angiosperm phylogeny of incorporating the Buxaceae within, or close to, the Trochodendrales will be assessed. Because the Trochodendrales occupy a central position in angiosperm phylogeny, the results will have important consequences for resolving interrelationships among major groups of flowering plants. The project represents excellent collaboration between the Australian and the U.S. scientist in combining their joint knowledge of the taxa to be considered and the techniques to be employed. Their complementary expertise on critical developmental, morphological and phylogenetic issues of flowing plants has the potential to signifi- cantly advance knowledge of the origin of flowering plants and phylogenetic models of the group. This is also important fundamental work on interrelationships among major groups of flowering plants, and has the potential to stimulate additional research using new molecular approaches to these problems.
