Revised treatment of the genus Lijndenia (Melastomataceae, Olisbeoideae) in Madagascar

Abstract

Lijndenia Zoll. & Moritzi (Melastomataceae, Olisbeoideae) is a small but widespread paleotropical genus of forest shrubs and small trees. In a previous treatment, Jacques-Félix recognized six endemic species of Lijndenia in Madagascar, namely Lijndenia danguyana (H. Perrier) Jacq.-Fél., Lijndenia lutescens (Naudin) Jacq.-Fél., Lijndenia melastomoides (Naudin) Jacq.-Fél., Lijndenia ramiflora Jacq.-Fél., Lijndenia roborea (Naudin) Jacq.-Fél. and Lijndenia terminalis Jacq.-Fél. The present work describes and illustrates three new Madagascan species : Lijndenia acuminata R.D. Stone, Lijndenia darainensis R.D. Stone and Lijndenia densiflora R.D. Stone. The name Lijndenia lutescens (Naudin) Jacq.-Fél. is found to be illegitimate, and a new name Lijndenia memecyloides R.D. Stone is proposed. With these revisions, the flora of Madagascar now holds nine species of Lijndenia, for which a formal taxonomic treatment is provided including a dichotomous key. Lectotypes are designated for Lijndenia danguyana, Lijndenia memecyloides and Memecylon meeusei H. Perrier (treated here as a synonym of Lijndenia memecyloides). The conservation status of each species is assessed according to the IUCN Categories and Criteria. Given the extensive anthropogenic deforestation of Madagascar, one must consider the possibility that Lijndenia acuminata, Lijndenia densiflora, Lijndenia ramiflora and Lijndenia terminalis are already extinct because these four species have not been recollected within the last 50 years. On the other hand, the recent rediscovery of Lijndenia melastomoides is remarkable because this species had not been seen since the year 1954. Résumé