Leaf phytognostic characters of six species of Hypericum L. (Hypericaceae)

Most of the studies on Hypericum genus deals with the phytochemical and pharmacological properties and the morphoanatomical data are scarce, although sometimes some species are poorly identified. In order to obtain differentiating phytognostic characters, the micromorphological, anatomical and histochemical study of mature leaves of six Hypericum species, H. androsaemum, H. calycinum, H. canariense, H. grandifolium, H. x inodorum and H. patulum, was carried out using different techniques of microscopy. Qualitative characters of both epidermal surfaces were evaluated: cell shape, cell wall, epicuticular deposits and stomata type. Only the last three characters showed some kind of differences. Five qualitative characters, stomata and gland indexes, total mesophyll thickness, palisade parenchyma and spongy parenchyma thickness, were subjected to analysis of variance on one factor ANOVA. Differences were found in the stomata and gland indexes as well as in the parenchyma cells arrangement and thickness. Histochemical tests were performed to localize and identify chemical groups of metabolites and the differences found were semi-quantitative. We conclude that the most important leaf phytognostic characters are: the epidermal cells shape, the type and distribution of stomata, the glands distribution and the mesophyll features