XVI International Botanical Congess

By 1941, more than 40 genera, many of them monotypic, had been described in tribe Gonolobeae, largely on the basis of great variation in the number and arrangement of corona structures. Woodson (1941) addressed this taxonomic confusion by reducing the genera to three (Gonolobus, Matelea, and Fischeria), arguing that the limited understanding of corona variation did not warrant further delimitations. A comprehensive revision of the tribe has since become even more necessary: many new species have been described, several genera have been reestablished, and it has become clear that Matelea, in particular, is an artificial group. We report the results of ongoing phylogenetic studies based on both morphological and molecular characters, and of developmental studies of the various corona components. Investigation of developmental changes (heterochrony) in a phylogenetic framework will help to uncover trends in corona character evolution and clarify the mechanisms underlying their diversity. This, in turn, will provide the basis for a meaningful classification of the tribe.