The Malpighiaceae comprise approximately 1250 species in 65 genera, with approximately 100 species belonging to the 15 Old World genera. Of the 100 species distributed across the Old World, 71 of them are endemic to Madagascar and belong to nine genera. These Malagasy taxa represent most of the major phylogenetic lineages within the family and are represented in as few as six and as many as nine independent clades. On a recent expedition to Madagascar I discovered a new genus and species of Malpighiaceae. Madagasikaria has a schizocarpic fruit with distinctive winged mericarps that possess a lateral wing, which completely encircles the nut, and a peculiar dorsal wing, which is folded over on itself. On the basis of ndhF and trnL-F chloroplast data, Madagasikaria is closely related to the Malagasy endemic genera Rhynchophora and Microsteira. These plants all appear to be functionally dioecious, and some of these appear morphologically to be androdioecious (which is a very rare breeding system in flowering plants). This has important implications for floral evolution within the family. Neotropical Malpighiaceae are pollinated by specialized oil-collecting bees and consequently exhibit highly conserved floral morphology despite tremendous diversity in fruit morphology and habit. These oil-collecting bees are absent from the paleotropics, where lineages lack the oil glands and typical flower orientation crucial to pollination by neotropical oil collecting bees. Based on my molecular systematic studies of Malpighiaceae the shift from the neotropical pollination syndrome has apparently taken place a number of times independently.

Key words: biogeography, floral evolution, Malpighiaceae, pollination biology