Study of the leaf petiole features of <i>Althaea Officinalis</i> L.

Aim – study of the leaf petiole features of Althaea officinalis L. for the selective diagnosis of medicinal plant raw materials. Material and methods. The objects of the study were samples of Althaea officinalis L. leaves. The sections for the study were prepared on the REF 901140 rotary microtome, SN S19112191. Anatomical and histological examination of Althaea officinalis L. plant materials were performed using polarizing microscope (PLM-213), light microscopes with a digital accessory in transmitted and reflected light with the ability to measure objects (Motic DM-1802, Motic DM-39) on a white field with x40, x100, x400 magnification. Sample preparation of raw materials and micro-preparations was carried out in accordance with the requirements of OFS.1.5.3.0003 State Pharmacopoeia of the Russian Federation, XV edition. Reagents were used to ensure histochemical reactions, which are regulated by the relevant GOST standards. Results. The anatomical and morphological study identified and confirmed new diagnostic features of the structure of the petioles of the leaves of Althaea officinalis L. consisting of a complex of the following features: variability of the outlines of cross-sections in the basal, medial and apical parts of the petiole; the characteristic structure and arrangement of conductive bundles and angular-lamellar collenchymes; the presence of idioblast cells with mucous lumps, calcium oxalate druses, trichomes on the epidermis, represented by simple unicellular hairs assembled into bundles of two or four cells and glands with a multicellular double-row head. Conclusion. The results obtained during the study can be used later in the revision of the section “Microscopic features” of the draft pharmacopoeial article “Althaea officinalis L. herb”, as well as in fundamental botany aimed at studying species of the Malvaceae family.