Taxonomia e anatomia de cinco espécies do gênero Maytenus (Celastroideae - Celastraceae) ocorrentes no Brasil

Abstract

Describes morphological and anatomical approaches to study the Genus Matenus Mol. Emnd. Mol. (Celastraceae). The genus is the largest in the family Celastraceae with around 200 species distribute throughout the tropics and sub-tropics of the Old and New World. In Brazil, the genus is represented by approximately 80 species. Maytenus is a polyphyletic genus and additional research is required to better understand its taxonomy. Maytenus ardisiaefolia Reiss., M. brasiliensis Mart., M. cestrifolia Reiss., M communis Reiss. and M. obtusifolia Mart. are difficult to identify because of similarities in their reproductive structures and variations in the size and shape of their leaves. The taxonomy of these species includes descriptions of leaf anatomy and external morphology. Pertinent comments about the morphology, taxonomy, geographic distribution and habitat are presented along with illustrations and a key to identify each of the five species. Anatomical studies, when combined with the external morphology studies, proved to be extremely useful at resolving the taxonomy of these species. The presence of two sub-epidermal layers in M. obtuisfolia and the absence of acicular crystals in the epidermal cells of M. cestrifolia were used to delineate these species. Here, the occurrence of cork warts on both faces of the leaf epidermis is reported for the first time for the genus Maytenus. Statistical analysis of morphometric characters helped to establish and describe a standard size and form for the leaves of these species. Mayteus ligustrina Reiss. e M. glazioviana Loes. are proposed as being synonyms for M. brasiliensisI and M. communis, respectively.