Mitra Noori, Habibeh Afzali Naniz Department of Biology, Faculty of Science, Arak University, Arak 38156-8-8349, Iran Euphorbia is the largest genus of Euphorbiaceae widely distributed all over the world. The genus members grow naturally in different parts of Iran and nearly 96 species of Euphorbia have been listed in the country. Investigations show that the traits of foliar epidermis have taxonomic values. That is why the features of epidermal leaf anatomy of 18 Euphorbia taxa were studied in the present study. Plant samples were collected from Kerman Province, Iran, and identified using available references. Semi-permanent slides were prepared of adaxial and abaxial leaf epidermis. Then the slides were studied using light microscopy and some epidermal leaf anatomy characteristics stomata types, trichomes, the shape and type of epidermal cell, and their walls were examined. Photomicrographs were taken from each sample. Results showed that stomata type were stable among the species. Not only leaf epidermal cell shapes differed between the taxa, but also in some species they varied between the abaxial and adaxial surfaces. These conditions hold true for cell wall patterns. Some of the studied taxa had simple and uniseriate trichomes on the epidermal surfaces, in most of them trichomes were present on both leaf surfaces, while in one species trichomes were seen on the abaxial surface. Our findings confirmed that some of the anatomical traits, such as the absence or presence of trichomes, epidermal cell shape, and anticlinal cell wall patterns had taxonomic value and are useful in the identification of taxa.
