Taxonomical identity of Schinopsis lorentzii and Schinopsis marginata (Anacardiaceae)

Abstract

Schinopsis lorentzii and S. marginata are closely related species that have been mainly differentiated by the shape, apex and color of the folioles, and also by their physiographical and altitudinal distribution. Nevertheless, these characters are intermediate and confusing between both species. In order to evaluate whether S. lorentzii and S. marginata can be differentiated on a morphological basis, the relationships among 89 specimens of both species were studied. A matrix of 29 morphological characters was analyzed by clustering and ordination methods. Both the dendrogram and the distribution of specimens in the Principal Components Analysis suggest that the limit between both species is not clear and none of the morphological characters are useful to differentiate them. We conclude that the morphological variations are related to altitudinal gradients and, consequently, S. marginata is placed under the synonymy of S. lorentzii (syn. nov.). The species is described and illustrated. A lectotype for Loxopterigium lorentzii is designated.