Abstract
Madagascar is a regional diversity centre of the plant genus Erica L. (heathers; anjavidy in Malagasy), with 35 species currently recognised. There is no modern taxonomic treatment of the group, and many collections remain unidentified. We review the taxonomic history of Malagasy Erica, built largely on the 1927 revision by Perrier de la Bâthie, who treated them as Philippia. We summarise diagnostic species descriptions and incorporate them into the Erica Identification Aid. There is clearly morphological variation that is poorly reflected in current species concepts and requires further study. Malagasy Erica most likely form a single radiation also encompassing species from the Mascarenes, according to published and new phylogenetic data. However, resolution within the group is poor, and most species remain unsequenced. Literature and specimen records show that Erica is found in all regions of Madagascar except the dry west and southwest, with the highest species richness on the high mountains. Habitats include the high-altitude “ericoid thickets”, shrubland–grassland mosaics in the central highlands and on the eastern coast, and Uapaca bojeri (tapia) savanna. The ecology of individual Erica species is insufficiently known. There may be both wind- and (currently undocumented) insect-pollinated species. Many Erica species are likely to be part of dynamic ecosystems with infrequent fire regimes. The paleorecord indicates a more widespread ericoid shrub vegetation during the last glacial period. Erica is mainly used as fuelwood, but local uses as tools and medicine have also been reported. None of the Malagasy species has had its conservation status assessed, but estimates suggest at least one-fifth of the species may be threatened. Taxonomic revision of the group, coupled with phylogenomics, is an urgent priority. This would also enable better assessments of ecological variation, local uses and conservation priorities.