In Poland, Borago officinalis is a cultivated plant or a segetal weed. It is a medicinal, cosmetic, melliferous, ornamental, and edible species. Its leaves, herb, flowers, and seeds are a source of bioactive compounds. Given the high concentration of essential fatty acids, borage is used in many branches of industry. | Turkish Journal of Botany Turk J Bot (2018) 42: 298-316 © TÜBİTAK doi: Research Article Histochemistry of glandular trichomes and the structure of selected organs of Borago officinalis L. 1, 2 Mirosława CHWIL *, Andrzej BOROWY Department of Botany, University of Life Sciences in Lublin, Lublin, Poland 2 Department of Horticultural Nursery and Seed Production, University of Life Sciences in Lublin, Lublin, Poland 1 Received: Accepted/Published Online: Final Version: Abstract: In Poland, Borago officinalis is a cultivated plant or a segetal weed. It is a medicinal, cosmetic, melliferous, ornamental, and edible species. Its leaves, herb, flowers, and seeds are a source of bioactive compounds. Given the high concentration of essential fatty acids, borage is used in many branches of industry. The aim of this study was to examine the structure of trichomes and to carry out histochemical labeling of selected groups of biologically active compounds contained in secretory cells. Anatomical traits of leaves, stems, and pedicels were investigated using bright-field light, fluorescence, and scanning electron microscopy. Characteristic features of the anatomical structure imply ecological adaptation of B. officinalis to xerothermic habitats. The trichomes in B. officinalis were divided into two groups. The first group included mechanical trichomes, whereas glandular trichomes formed the other group. Three hair types were distinguished in each group. Various groups of secondary metabolites were identified in exudates using histochemical assays. These investigations are a basis for identification of the location of selected groups of biologically active compounds such as essential oils, fatty compounds, neutral lipids, phenolic compounds, flavonoids, polysaccharides, and calcium in B. officinalis. Key words: Borage, micromorphology, biologically active substances, stomatal index,
