The lichen family Megasporaceae includes 5  accepted gerera i.e Aspicilia, Circinaria, Megaspora, Lobothallia, Sagedia and one informally accepted genus Sphaerothallia. It is expected that the family consist of ca. 300 species worldwide. They are mainly crustose, foliate to subfruticose, and are simple to highly differentiated in structure. The main emphasis of the present project will be on the species occurring in the Iranian and the central Asian steppes and deserts, However, beside main collections from Iran, material from (Europe, N America and Australia) from certain species groups will be studied utilizing anatomical, morphological, chemical, ecological and molecular data as well as some