Leaf morphoanatomy of the medicinal Maytenus imbricata (Celastraceae): an ecological approach

<p><em>Background</em>. The leaves of many species of <em>Maytenus</em> are used to prepare herbal drugs to treat stomach ulcers.</p><p><em>Questions.</em> In order to define key anatomical characters for the unambiguous species identification, the present study aimed to describe the leaf morphoanatomy of <em>M. imbricata.</em></p><p><em>Species study</em>. <em>Maytenus imbricata</em> Mart. ex Reissek (Celastraceae)</p><p><em>Study site and dates.</em> Collected in an area of ‘campo rupestre’ - one of the Brazilian Savannah vegetation (20º22’11.02”S, 43º30’22.81”W) in August 2015.</p><p><em>Methods</em>. The plant material was processed according to commonly used techniques in plant anatomy studies.</p><p><em>Results. </em>The major anatomical characters for several species of <em>Maytenus</em> identification also present in <em>M. imbricata</em> are marginal teeth, conspicuous epicuticular wax, ciclocytic stomata, thick external periclinal wall with large pits on epidermal cells and vascular system with a closed loop shape in cross-section. Strips on the anticlinal walls on epidermal cells and conspicuous gelatinous fibers sheath are diagnostic for <em>M. imbricata</em>.</p><p><em>Conclusions.</em> Strips on the anticlinal wall of the epidermal cell are reported for the first time for the genus. These xeromorphic traits help the species to survive in arid environments and may contribute to quality control of the raw material used in the production of herbal medicines.</p>