Abstract

The purpose of the present study is to determine some morphological and anatomical characteristics of the species of Hypericum montbretii Spach., H. origanifolium Willd. and H. perforatum L. that show natural distribution in Eskişehir and its surrounding area. H. perforatum was determined to exist more abundantly in the research area in comparison with H. montbretii and H. origanifolium. While H. montbretii and H. origanifolium have black glands, H. perforatum lack such glands. Upon the examination of the root cross-rections, the pith was determined to be completely covered by xylem cells. As to stem cross-sections, it was observed that large parenchymatic cells were present in the pith of the young stems, while old stems were observed to have formed cavity in their pith. The species examined were determined to bear resemblance to one another in consideration of their leaf anatomy. Leaves are equifacial and amphistomatic and they have amaryllis type stomata. They are mesomorphic and there are schizo-lisigenous type secretion pockets in the leaves. Compared to adjacent cells,stomata are anisositic or diasitic. Stomata on the lower surface of the leaves show higher frequencies than those on the upper surface.