A Synoptic Revision of the Malagasy Endemic Euphorbia pervilleana Group

The non-succulent, leafy species of Euphorbia from Madagascar have received considerably less attention from taxonomists than the succulent Euphorbia species. The lack of a recent synthetic taxonomic treatment for this group makes it almost impossible to accurately name these species. As part of an ongoing revision of the genus in Madagascar, Euphorbia randrianjohanyi and Euphorbia rauhii , two new species closely allied to the Malagasy endemic E. pervilleana are described, and a key to these three species is provided. This group is distinguished by echinate 1–2-locular capsules. It is closely related to other Malagasy species such as E. tetraptera, which possesses 2-locular capsules with four wings. The three species are dioecious and their deciduous leaves can make some specimens difficult to distinguish; however they can be separated by their allopatric distribution, the length of interglandular appendages, the shape and size of the leaves, as well as by fruit features. They all occur in the central and southern part of the island.