Microscopic analysis of Valeriana stolonifera and Valeriana collina leaves

Plants of the Valeriana species are distributed in various parts of the world, especially in Europe and Asia. A high content of polyphenolic compounds, including flavonoids and hydroxycinnamic acids with expressed biological activity, was previously identified within the herb of the studied Valeriana species. Morphological and anatomical data can be used in phylogenetics of species and genera to find out diagnostic and age-related characteristics of plants. This led us to microscopic studies of aerial organs of the above-mentioned Valeriana species. The aim of the work is to conduct a comparative study of the diagnostic features within the morphological and anatomical structure of Valeriana stolonifera and Valeriana collina leaves. Materials and methods. Both raw and dried plant material of V. stolonifera and V. collina was used for microscopic studies. Temporary micropreparations were made using generally accepted methods. The anatomical features of the raw material were examined using Carl ZEISS “AxioStar Plus” and “Primo Star”. Results. The study identified key morphological and anatomical features of the species, which should be considered for the identification and standardization of promising medicinal plant materials and within the development of methods of analytical and regulatory documentation. Conclusions. The key microscopic differences in the leaves of the studied species lie in the structure of the adaxial and abaxial surfaces of the leaf blade. The upper epidermis consists of large elongate cells with wavy walls. The cells of the lower epidermis are smaller and have more sinuous walls compared to the upper epidermis cells. The degree of wall sinuosity varies between species – V. collina is characterized by more sinuous cells in both the upper and lower epidermis compared to V. stolonifera. The absence of stomata on the upper epidermis is a common feature for both species.