Excluded sp: Memecylon myrtiforme Naud.
Madagascar contains the greatest concentration of species within the widespread paleotropical genus Memecylon. All of the Malagasy spp are endemic to the island, and the majority are local endemics known from 1 or 2 sites. Recent field & collections-based studies will result in the addition of about 50 new species to the 89 species previously recognized (R.D. Stone, in prep.). Convergence in vegetative features has led to taxonomic confusion; it is therefore important to take ecogeographic factors into account.
Phylogenetic evidence favors the hypothesis of an African origin for Memecylon; the occurrence of the genus in Madagascar and tropical Asia must therefore be the result of "out of Africa" dispersal. Based on limited taxonomic sampling, the Malagasy spp form a monophyletic group, suggesting that a single colonization event gave rise to the extensive radiation of Memecylon. If a robust, species-level phylogeny can be obtained, then Memecylon could prove to be an important model system for investigating mechanisms of species diversification in Madagascar
Unidentified, undescribed specimens: Perrier 32, Perrier 18418, RN 9005, SF 23813, SF 28110, SF 17940.