Laktionov Alexey P.  -  D. Sc. (Biology), Professor, Astrakhan State University named by V.N. Tatischev: All-Russian Research Institute of Forest Genetics, Breeding and Biotechnology, Shaumyan Sq., 1, Astrakhan, 414000, Russia, Lomonosov st., 105, Voronezh, 394087, Russia ,

Voloboeva Oksana V.  -  post-graduate student, Astrakhan State University, Shaumyan Sq., 1, Astrakhan, 414000, Russian Federation,

Ten to fifteen thousand years ago, the Bolshoy Bogdo mountainwas a refuge island in the Khvalyn sea. Eight relict species of plants of the Tertiary period have been preserved on the Bolshoy Bogdo mountain and in the adjacent territory of the Bogdo-Baskunchak salt dome region. All of them have a disjunctive Iranian-Turanian area. The boundary of the main part of the area of relict plant species ends on the slopes of the chinks of Northern Ustyurt.The habitats of most species of relict flora of the the Bogdo-Baskunchak salt dome regionare confined to the ancient seaside terraces of the Bolshoy Bogdo mountain with a well-defined abrasive coastline on its slopes. It can be assumed with great confidence that relict species were also distributed on other salt-domed elevations of the Northern Caspianregion before the Khvalyn transgression of the Caspian Sea. During the island isolation of the Bolshoy Bogdo mountain, a neoendemic element of its flora was formed on it.

Key words: the Bogdo-Baskunchak salt dome region, the Bolshoy Bogdo mountain, the Northern Caspian, relict, endemic, flora