Study of Flora Resistant to Drought with the Aim of Recognition and Conservation of Adapted Established Plant Species in Sistan

Low precipitation, high evaporation, 120-day winds, low altitude, salinity and dryness of soil have caused severely disturbance of natural plant populations in Sistan. Environmental stress leads to some changes in plant morphology. Therefore, the plants grown in Sistan such as, Salsola imbricata and Suaeda vermiculata are given some traits including thick cuticle and wax, succulent organs, and non-deep and expanded roots on the soil surface that allow them to survive in salty and dry soils. Some species such as Fortuynia garcinii and Halothamus subaphyllus are armed with a wax layer on the plant surface that prevents water loss. Some species such as Anabasis aphylla, Stocksia brahuica and Lycium depressum avoid water shortage via reducing leaf area and falling leaves during dry season. In the plant species Alhagipseudalhagi, Capparis spinosa and Prosopis stephaniana both the deep and shallow roots are present, so they utilize the rain and sub-ground water concurrently. Furthermore, ephemeral plants e.g., Stipa sp., reduce the time period to seed production. They fall the seeds into the soil prior to dry season. Totally we collected and identified plants form 35 families, 121 genus, and 127 species that mostly belonged to Asteraceae and Chenopodiaceae families.