ANATOMICAL STUDIES OF THE GENUS POA L. IN IRAN

The genus Poa L. is the type of Poaceae family, having 500 species all over the world. It has been distributed well in both hemispheres. Identification of the genus has been associated with taxonomical and identification difficulties; therefore it seems that using of methods of biosystematics is useful. Since inner structures of organs do not vary despite environmental changes, anatomical studies are helpful. Microscopically study of lamina is preferential in Poaceae because of its well availability and mature, specialized and independent structure of reproductive stage. In this study, leaf transects of the taxa of the genus Poa in Iran are compared. 84 characters for leaf structure were investigated. List of them are presented in this paper. Among them, always 40 characters are constant in all taxa. 44 variable characters have taxonomical value and can be used for distinguishing between taxa. Anatomical key of taxa and photos of transects are presented.