Leaf anatomical and morphological characters of some species of Acer

Acer L. contains about 148-150 species that are almost all distributed in Asia, China and Japan. 10 species of Acer are the principal component in Iran forests. The presence of unidentified and hybrid species, and influences of environmental changes on morphological traits, have further complicated the confusion over species grouping in species. This work was initiated with the objective of the morphology and anatomy of leaf and wood of existing taxa in Iran to identify and establish their similarities and dissimilarities relationship between them. Thus, we observed 52 quantitative and qualitative characters from leaf and epidermis. Cluster analysis Ward and Principal components analysis (PCA) were done in R sofware. PCA obtained the same result of the cluster analysis. Results showed that all Acer species were classified in a major cluster and distinct from two other species Koelreutaria paniculata and Dodonea viscosa. A. campestre and A. microphyllum had the most morphological similarities and also other species A. negundo united with them in cluster seperately. Different clusters of species showed that two kind of attributes are responsible for seperation and distinction between species. Leaf anatomical characters such as midrib thickness, the presence or absence of trichomes, different shapes and size of trichomes, trichome density, thickness and variety of epicuticular waxes and their shapes, size and stomatal density, bundle sheath form and amphicribral vascular bundle varied from species to another. It appears that differences and similarities among species are related to ecological environment and habitat conditions.