Relevance. It is known that peppermint (Mentha х piperita L.) is characterized by significant polymorphism, due to both genetic factors and growing conditions. Cultivated varieties and populations are distinguished by their economically significant characteristics, such as yield, winter hardiness, resistance to diseases, the content and composition of essential oil. Identification of new highly productive varieties and populations of Mentha x piperita L., distinguished by high productivity of essential oil in the Non-chernozem zone of the Russian Federation, as well as identification of morphological features characteristic of highly productive varieties, remains relevant.Methods. The object of the study was plants of 8 varieties of 2 year old plants and samples of Mentha x piperita L. from the collection of the SI Botanical Garden Rostovtsev RGAU-Moscow Agricultural Academy named after K.A. Timiryazev and from the collection of the Botanical Garden of All-Russian Institute of Medicinal and Aromatic Plants (VILAR), were used as the object of the study. Peppermint leaves (FS.2.5.0029.15 Peppermint leaves) and essential oil (GOST R 53593-2009) are used as herbal medicinal products. Microscopy used Primo Star Carl Zeiss light microscopes and LOMO MIKMED-1. Quantitative determination of the essential oil was carried out by distillation with water vapor, followed by measuring the volume of the resulting oil (GF RF XIV). The oil content was expressed in volumetric-weight percent in terms of dry raw materials.Results. As a result of a comparative study of the epidermal structures of the leaves of plants of 8 varieties of Mentha х piperita L., the density of stomata, the type of stomatal apparatus, density of location and length of multicellular trichomes, density and diameter of essential oil glands, and content of essential oil were determined. The variety specificity and variation of these indices are noted over a wide range, which is explained by the significant intraspecific variability characteristic of the genus Mint (Mentha L.). The most promising varieties of essential oil content were identified.

The results presented in the article concerns the variety productivity of annual and biennial peppermint rhizomes grown on sod-podzolic soils with successive and simultaneous addition of mineral, organic fertilizers and lime.