Systematics and phylogeny of Maytenus Molina (Celastraceae) on the Neotropical Region

Abstract

Celastraceae has about 1000 species with global distribution and Maytenus is the main genus in Neotropic with ca. 140 species, in practically all vegetation types. The species are characterized by alternate leaves, instrastaminal disk, and capsular fruits opening by two or three valves. Maytenus presents low variability on reproductive characters and the identification is usually based on vegetative characters, such as the branches and the leaves. This project proposes the elaboration of a phylogenetic study using morphological and molecular data, from plastid (matK and trnl-F) and nuclear (ITS and 26S). The principal aim of this project is clarify the position and relationship of species within genus and with other genera, as Fraunhofera and Plenckia. These two genera appeared nested with Maytenus in preliminaries phylogenies, though any synapomorphies have been identified for the group as a whole. The phylogenetic analysis will also serve to propose a new infrageneric classification based on natural groups, since the other former proposed are clearly not monophyletic. The phylogeny obtained will permit to characterize natural groups, identify synopomorphies and resolve questions regarding "complex" of species, and taxonomic decisions will be taken from it. (AU)