Anatomical investigations on eleven Hypericum L. taxa

In this study, anatomical features of Hypericum capitatum Choisy. var. luteum N. Robson, H. lydium Boiss., H. malatyanum Peşmen, H. microcalycinum Boiss. & Heldr., H. perforatum L. H. retusum Aucher, H. scabrum L., H. spectabile Jaub. & Spach, H. thymopsis Boiss., H. triquetrifolium Turra and H. uniglandulosum Hausskn. ex Bornm. from Türkiye were examined. The cross-section of the root, stem and leaves were investigated with light microscopy. The leaf surfaces were examined with scanning electron microscopy. The roots have 2-3 or 4-5 layers of periderm. The stem wings were various in shape and number, the epidermis is single or double layered. The leaves are equifacial or bifacial. The micro-anatomy of leaf surface show that the epidermis cell walls are straight to slightly undulate, straight to undulate or straight to curved and the stomata are anisocytic. The characteristics obtain from this study were aimed to make contributions to the diagnostic features of genus Hypericum.