Micro-morphology of Achillea clypeolata: contribution to the pharmacognostical profile

Achillea clypeolata Sibth. & Sm. is Balkan endemic species, commonly known as yellow yarrow and traditionally used in Bulgarian folk medicine. The purpose of this study was to establish pharmacognostical profile of A. clypeolata, including macroscopic and microscopic morphological characteristics. The study also aims to propose a method for micromorphological investigation and pharmacognostical identification. As a result were established morphological characters necessary for identification of Achilleae clypeolatae flos and Achilleae clypeolatae herba – morphology of stem leaves (lanceolate in shape, pinnately lobed-margin, acute-apex with lamina), ligule petals (2.7-3 mm), involucre bracts (4.5x2 mm) and achenes (1.5-1.7 mm); micromorphology of lamina (110-130 μm), epidermal cells, stomata, glandular, non-glandular trichomes and 3-colporate, echinate pollen grains (20.5-20.8 μm). This study presents new micromorphological data. The used staining method dyed various tissues; makes visible the outlines of structures, tissues and some inclusions; allows by one procedure to visualize important diagnostic features; unlike many other methods, allowing pollen to be used as a characteristic of herbal substances. The results are useful for quality control methods for medicinal plant materials and contributes to the implementation of good practices for plant identification for the herbal industry, food, nutrient supplements and other plant based products.