ANATOMICAL ASPECTS OF THE STEM AND LEAF OF MENTHA x PIPERITA L. (LAMIACEAE)

Mentha x piperita (Lamiaceae) has been known since ancient times due to its aromatic and therapeutic properties. The differences in essential oil composition among the members of the genus Mentha offer a diversity of strains with high contents of menthone, menthol, carvone, linalool, or other valued terpenoid components synthesized by the mevalonic acid pathway. The species was analyzed anatomically. As biologic material, stems and leaves have been sampled from crops, during the vegetation period, before blooming. From an anatomical point of view, transverse sections were made through stems and leaves. At the level of the epidermis, both in the stem and in the leaf, the secretory and the tector trichomes were highlighted. The foliar limb is hypostomatic, with stomata in the inferior epidermis, the stomata being of the diacitic type. The mesophilus of the foliar is bifacial, having palisadic tissue with a single layer of cells, located under the superior epidermis and lacunar tissue, located under the inferior epidermis.