Anatomo-diagnostic traits of lemon leaves (Citrus limon (L.) Burm. f.)

The article summarizes the results of studying the anatomical structure of the leaves of a medicinal lemon plant (Citrus limon (L.) Burm. f.) from the Rutaceae family, which is used in the pharmaceutical industry to produce valuable lemon essential oil with antibacterial and antioxidant properties. There is no complete information about the anatomical structure of lemon leaves in the literature, which makes it challenging to conduct microdiagnosis of medicinal raw materials. Therefore, the study of the anatomical features of lemon leaves is relevant. The researchers took the medicinal plant material of the fresh leaves of Citrus limon from the greenhouse of the Botanical Garden named after S.I. Rostovtsev. They carried out anatomical analysis of raw materials and histochemical reactions according to the regulatory documentation of the State Pharmacopoeia of the Russian Federation. The microscopic structure showed that the leaves of Citrus limon are dorsoventral, the leaf blade is hypostomatic. The stomatal apparatus of the leaves is anomocytic. In the leaf, endogenous secretory structures were observed, represented by round-shaped lysigenic essential oil receptacles formed in the columnar and spongy mesophyll of the leaf and the main petiole parenchyma. The essential oil was synthesized in the secretory cells of the receptacle, which eventually underwent autolysis and released contents into the resulting cavity. A collateral conductive bundle with a ring-shaped cross-section represents the central vein of the leaf blade and leaf petiole. The characteristic marker features of the leaf also include the presence of single rhomboid crystals and drusen calcium oxalate in the leaf petiole mesophyll and parenchyma. As a result of the studies, significant anatomical and diagnostic signs of Citrus limon leaves were found, which can be used in writing pharmacopeia articles.

Citrus limon (L.) Burm. f, pharmacognosy, microscopic analysis, anatomo-diagnostic traits, leaf anatomy, essential oil, lysigenic essential oil receptacles

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