Micro-morphological features of leaf like stomata and trichomes are reliable indicators of plant responses to environmental conditions. The aim of the work presented here was to determine the adaptive strategies of 10 woody species growing in semi-arid Zagros forests in western Iran, based on leaf microstructures, focused on trichome and stomata structures using light and scanning electron microscopy. Varied types of trichomes and stomata were recognized. Stomata were usually more visible on the abaxial sides of the leaves, a trait which helps reduce water loss from foliage surfaces exposed to direct air flow and irradiation. Trichomes were categorized in two different types: glandular trichomes and non-glandular trichomes with sub-groups including solitary, two armed T-shaped unicellular, crypt, hooked hairs with cystoliths, fasciculate, stellate, long coiled, tufted stellate, long multiradiate, short bristle with cystolith, peltate scale and dendritic hair. The abundance of trichomes on leaves indicates their role as a biological control parameter. Eucalyptus camaldulensis was the only species examined with no trichomes on either side of the leaf. Anomocytic and paracytic stomata were the most common types observed. Leaf micro-morphological features clearly differed between species and probably represent adaptations of the plants to the ambient ecological conditions.
