Leaf and stem anatomy in eight Hypericum species (Clusiaceae)

Abstract

Foliar micromorphology, epicuticular wax morphology and anatomical featuresof leaves and stem, particularly secondary xylem, were examined with light microscopy,general and histochemical staining and scanning electron microscopy in eightHypericum species. Outer tegument tissue and type of secondary xylem are determiningcharacteristics. 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.