Microscopical Investigation of Sideritis taurica

This research presents the results of the morphological-anatomical study of grass organs above ground (leaves, stems, and flowers) from Sideritis taurica Steph. ex Willd. from the Lamiaceae family. The range of distribution of this species covers Eastern Europe, including Crimea, Caucasus. This plant is commonly found as an ornamental plant and grows in the southern and central regions of Russia. The purpose of this study is the anatomical and morphological study of the vegetative organs of S. taurica and the formation of diagnostic signs for reliable plant identification. The research material used was S. taurica herbicide samples collected in Crimea on the slopes of Mount Ay-Petri. Plant material is fixed in the glycerin : water system in a ratio of 1 : 1. Cross-section of stems and leaves is carried out using blades. The study was conducted with the morphological-anatomical method. The results obtained indicate the anatomical structure of the lamina, stem, and flower of the plant that has been studied. Anomocytic types of stomatal devices, unicellular and multicellular trichomes, located on the upper and lower sides of the leaf, as well as on the corolla stem and epidermis, have been discovered. The study carried out is part of the S. taurica complex pharmacognostic study.

Diterpenoids are among the most common and essential pharmacological interests of the classes of natural compounds presented in S. taurica. Leaves, stems, and flowers contain iridoids. Fatty oil 29-30% was found in the seeds, in its composition acids: palmitic, stearic, oleic, linoleic, linolenic. Crimean Sideritis is considered a natural immunomodulator. The essential oil composition of S. taurica was studied; the main components of α-bisabolol and α-pinene were isolated (Aljančić et al., 1996;Ellman et al., 1961). The determination of flavonoids in the genus Sideritis is described by a novel reverse-phase high-performance liquid chromatography method. The content of ethyl acetate extract of sixteen species of the genus Sideritis in chrysoeriol, apigenin, sideritoflavone, xanthomycrol, gardenin D, 8-methoxycyrsilineol, and desmethylnobiletin is reported (Palomino et al., 1996).
Various studies related to S. taurica have been widely reported before, although most of them were reported over the last 20 years. Interestingly, there are barely any studies reporting microscopic studies of these plants.
Therefore, this study tries to complete the missing puzzle from S. taurica research by conducting an in-depth investigation of the plant's microscopic study. This study aimed to provide information regarding the diagnostic features of both the vegetative and generative organs of S. taurica.

Morphological investigations
Sideritis taurica is a perennial herb with a stem densely covered with felt hairs and woody at the base.
Stomatal apparatuses are present on both sides of the leaf blade. They have a diacytic type, which is characteristic of representatives of the spongy family, including the genus glandular. The epidermis' primary cells differ in the degree of tortuosity of the anticlinal walls (Figures 3-4A -

3-4B).
The epidermis of the flower's calyx is similar in structure to the lower epidermis of the leaf plate, characterized by tortuous epidermal cells, diacytic stomata, and numerous trichomes in the form of head and simple multicellular hairs with characteristic expansion in the cell junction zone (Figures 3-5A -3-5C).
The corolla epidermis is characterized by rectangular or polyhedral elongated cells, with a thickened cell wall, trichomes are absent (Figures 3-6A -3-6C). Stomata are absent also. Microscopical Investigation of S. taurica has never been reported before, so this study's results are expected to complement the research data related to S. taurica. Sideritis taurica itself is still quite widely researched, especially in relation to the various metabolites' pharmacological activity (Aneva et al., 2019;Tunalier et al., 2004). Fatty acids, hydrocarbons, α-amyrin, stigmasterol, and β-sitosterol were identified in the nhexane extract of the air portions of S. taurica. Analysis of GC-FID and GC/MS showed that the two oil samples were identical in composition but differed in percentages of some components. The composition of essential oils of the species was investigated by HA and GC mass spectrometry. They were characterized by the presence of a high percentage of monoterpene hydrocarbons (Kirimer et al., 2003;Ezer et al., 1996). taurica oil as an antitumor agent and testing the correlation between the increased antitumor activity of essential oil with its high oxygen content (Navarro et al., 1997;González-Burgos et al., 2013;Ezer et al., 1996).
Studies related to the microscopical investigation of a medicinal plant itself are generally carried out on a plant that is well known for its pharmacological activity and its various secondary metabolites (Ketjarun et al., 2016). In addition to the purposes of identifying and authenticating medicinal plants (Song et al., 2020), micromorphological investigations will also provide detailed information if there are differences at the microscopic level of several different plant species and sub-species but still in the same genus and has never been identified before (Jachula et al., 2018;Konarska, 2017).
Related studies of the genus Sideritis have previously been reported by Türkmenoğlu and Duman (2015) as well as Rejdali (1991), but have never been carried out on S. taurica. Thus, the results of this study will provide novelty for the development of various studies on S.
taurica and other plants from the genus Sideritis.

CONCLUSION
The micromorphological study of vegetative and generative organs of S. taurica were reported for the first time. The diagnostic features were established for reliable identification of the plant, such as the trichomes represented by simple unicellular and multicellular hairs; a beam type conductive system; hairs located in the structure of both epidermis of the leaf, as well as on the epidermis of the stem and calices, but not specialized for the epidermis of the corolla.