Leaf and stem anatomy in eight Hypericum species (Clusiaceae)

Foliar micromorphology, epicuticular wax morphology and anatomical features of leaves and stem, particularly secondary xylem, were examined with light microscopy, general and histochemical staining and scanning electron microscopy in eight Hypericum species. Outer tegument tissue and type of secondary xylem are determining characteristics. Secondary xylem is ring-porous in H. perforatum, H. perfoliatum, H. tetrapterum, H. triquetrifolium, H. androsaemum and H. hircinum. In H. aegypticum and H. pubescens xylem is diffuse-porous, which is considered to be a more primitive type. These characteristics may be considered an additional criterion for species identification.