DISSERTATION RESEARCH: Phylogeny of Caesalpinioid Legumes from the Guyana Shield

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The legume family (650 genera/~18,000 species) is the third largest family of flowering plants and the second most economically important family. The subfamily Caesalpinioideae has received relatively little attention and recent morphological and molecular evidence suggests this subfamily may not be a natural group. Part of the reason for the uncertain status and relationships of the members of the Caesalpinioideae is that many of the genera and their species are poorly known and rarely collected. The study of plant taxonomy and phylogeny is inherently dependent on field work, many times in remote areas, which is the case for caesalpinioid legumes in general, and in this study in particular. The research outlined in this proposal will provide monographic revisions and species-level phylogenetic hypotheses for a group of poorly known caesalpinioid legume genera that are endemic to the Guiana Shield area of South America (Venezuela, Suriname, French Guiana, and Guyana). Funding from the NSF DDIG program will allow Ms. Redden to travel to museums in Venezuela and Europe to examine herbarium material that is needed for this study, and to conduct field work in southern Venezuela to collect plant specimens, dried leaf samples, and pickled flowers for study. A total of five weeks will be spent in the Sierra de la Neblina area of Venezuela. While in Venezuela, Ms. Redden will also visit five herbaria to gather information on plant characteristics and distribution for the monographic and phylogenetic aspects of this study. The primary objectives Ms. Reddens dissertation are to provide a systematic revision of five key genera of the group (Dicymbe, Paloue, Paloveopsis, Heterostemon and Elizabetha) and to study morphological evolution, especially floral morphology, in this group.Working directly with Venezuelan scientists, students, and local communities is an essential part of this study. These activities will enhance collaboration with Venezuelan botanists, including students, and will contribute to broader studies of relationships within Caesalpinioideae. While conducting research in the Venezuelan herbaria Ms. Redden will examine and photograph specimens, verify identifications, and identify unknown material wherever possible. In addition to locating important specimens for her research, Ms. Reddens herbarium work in Venezuela will help to improve their collections. We have been working with Dr. Basil Sterigos with the Universidad Nacional Experimental de los Llanos Occidentales Ezequil Zamora(UNELLEZ) in planning the field work. Dr. Stergios and his student will accompany Ms. Redden on the field expedition. This expedition will not only contribute vital information to the dissertation project, it will also document biological diversity in Venezuela. Voucher specimens will be made for the Smithsonian Institution (US), Herbario Universitario BioCentro-UNELLEZ (PORT), and Herbario Nacional de Venezuela (VEN). In addition to the plant collections, all other information will also be shared with UNELLEZ. Photographs, GPS coordinates, field notebooks, and other data also will be copied and left with UNELLEZ.