New species of Memecylon (Melastomataceae) from Madagascar: treasures of the TEF Herbarium

Abstract STONE, R.D. (2020). New species of Memecylon (Melastomataceae) from Madagascar: treasures of the TEF Herbarium. Candollea 75: 219–239. In English, English and French abstracts. Memecylon L. (Melastomataceae, Olisbeoideae) is a widespread paleotropical genus of forest shrubs and small trees, and is one of the ten most species-rich genera of woody plants in Madagascar. In a previous treatment, Jacques-Félix recognized 78 species of Memecylon on the island, of which all are endemic and most are known from just one or two sites. The present work describes and illustrates nine new species of Memecylon from Madagascar (including Memecylon complanatum R.D. Stone, Memecylon convergens R.D. Stone, Memecylon fofifa R.D. Stone, Memecylon longipetiolatum R.D. Stone, Memecylon paraxenum R.D. Stone, Memecylon potamicum R.D. Stone, Memecylon pseudogaleatum R.D. Stone, Memecylon subchartaceum R.D. Stone, and Memecylon unguiculare R.D. Stone), based mainly on material received on loan from the FO.FI.FA Herbarium (TEF). The conservation status of each species is provisionally assessed in accordance with the IUCN Red List Categories and Criteria. Given the extensive anthropogenic deforestation of Madagascar, one must consider the possibility that Memecylon complanatum, Memecylon paraxenum, and Memecylon pseudogaleatum are already extinct since these three species have not been recollected within the last 50–60 years. Work is ongoing towards a comprehensive taxonomic revision of Memecylon in Madagascar.