Study on Flora of Lut in Southern Khorasan

The first character of the desert is lack of water as well as the lack of vegetation. Although the number of plant species in arid lands is very limited, but these species have survived and adapted over the centuries. Due to the difficulty of entering Lut desert, during the last one hundred years, no research was done on plant species in Southern Khorasan part. Therefore, during 2017 to 2018, all perennial species in Lut were identified. The results revealed that a total of six species belonging to four genera and three families were identified. Chenopodiaceae with three species, Poaceae with two species and Polygonaceae with one species occupied 50%, 33.3% and 16.66% of the flora of the region, respectively. Stipagrostis and Haloxylon have the highest number of species. Geographical distribution analysis showed that Iran-Turan and Sahara-Sindi species are presented in equal proportions. Haloxylon persicuum Bge. ex Boiss. & Buhes, Haloxylon ammodendron Bunge ex Fenzl and Stipagrostis plumosa Munro exT. Anderson were distributed in the north and northeast. The highest distribution of Calligonum comosum L'Hér was observed in the west. Although the diversity was very limited and the 18-year droughts have intensified the drought of Calligonum and Haloxylon in many areas of Lut, however, increase in rainfall in 2019 in Lut increased hope for the survival of shrubs and increasing the amount of Stipagrostis species.