NOTE ON USE OF SOME MICRO-MORPHOLOGICAL FEATURES IN DISTINCTION OF 3 PUBESCENT OAKS IN CROATIA

The abaxial epidermis of pubescent oaks, Quercus brachyphylla Kotschy, Quercus dalmatica Radic and Quercus pubescens Willd., was studied wit h the Scanning Electron Microscope. Micro-morphological features (surf ace of trichomes, stomata, ordinary epidermal cells and wax) do not pe rmit to distinguish the three oaks species. Nevertheless, the differen ce among the taxa exist in leaf phenology and time of appearance and r ate of degradation of epicuticular wax crystalloids. Alteration of wax crystalloids into amorphous wax is interpreted in favour of natural p henomenon of the wax ageing and degradation.