Systematics of Clibadium (Compositae, Heliantheae)

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This Science in Developing Countries award will help to support thesis dissertation work of Mr. Jorge Arriagada of Concepcion, Chile working under the supervision of Professor Tod Stuessy of Ohio State University. The main objectives of the proposed research are: (1) to produce a taxonomic revision of the species of Clibadium, a Neotropical genus of approximately 40 species distributed from Mexico to Peru; (2) to determine the evolutionary relationships among these species; (3) to establish generic limits relative to Desmanthodium, Ichthyothere and Stachycephalum; and (4) to determine biogeography and suggest modes of speciation of the species. An ancillary objective of this research is to study variations and evolution of capitulescence structure and development of unusual drupe-like fruits in Clibadium for help in reconstructing phylogeny. As time permits, the ethnobotanical activities of the Indians in Latin America will be documented as they relate to use of Clibadium species as fish-poisons. The ethnobotanical role of the genus should provide an extra dimension to understanding the systematics and biogeography of the genus. To achieve these goals, a complete collection of plant material and field observations along the distributional range is needed. Morphological (including anatomical) and cytological data will be gathered, and reconstruction of phylogeny will be done by cladistic techniques. The proposed research is significant for several reasons. It will produce the first modern revision of the genus, including keys, descriptions and a predictive classification, valuable to botanists working on Neotropical floras. It will also provide the first phylogenetic reconstruction of the genus. In addition, understanding of evolutionary relationships within Clibadium should lead to an improved understanding of affinities with the related genera Desmanthodium, Ichthyothere, and Stachycephalum.