A REVIEW OF THE GENUS TILIA L. (TILIACEAE) IN IRAN, NEW RECORDS AND NEW SPECIES

Natural sites were selected as sampling areas in most parts of Hyrcanian forests to study the taxonomical parameters during 2005 – 2010. The range and frequency distribution of Tilia trees were studied via searching on the forestry projects and documents, local inquiry and finally controlling the field data towards finding the trees from each forest type during the study period. Corresponding field data included taxonomical details of the specimens and environmental variables. This also accounted for local morphological variation within the different sites of each ecosystem. All studies were performed on living and herbarium specimens, and on some of the most important local herbarium materials. Results of morphological study and biometry of specimens showed that there are clear differences between trees and herbarium specimens. According to summarized data from the obtained results, six distinct species were identified that include: Tilia cordata, Tilia dasystyla, Tilia rubra subsp. caucasica, Tilia begonifolia, Tilia sabetii and Tilia stellato-pilosa. Of these six species, the last two species are new to science. Nevertheless variation and presence of these species reveal high degree of diversity of this genus in Iran. To provide new identification key for the species, most important botanical characteristics and their ecology and geographical distributions are described.