Geographical analysis of xerophytes flora of the Russian Caucasus

The aim of our research was to study geograph-ical elements, xerophytes flora of the Russian Cau-casus in connection with the questions of the gene-sis of knowledge. The study was based on field research expeditions, on the territory of the Russian Caucasus. The collection of herbarium material was carried out by a traditional route in combination with the detailed study of the most interesting floris-tic complexes. The main method of floristic data was fixing herbarium collections. In the course of the study the recording environmental observa-tions, height and features phytocenotic species was done. Geographical analysis of the Russian Cau-casus xerophytes flora, numbering 1 018 species of vascular plants was performed. Within the study the area of 6 groups of geoelements was marked as belonging to the highest hierarchical botanical-geographical zoning units. The analysis shows that among geographic elements in the studied flora the vast majority of the flora xerophytes makes boreal geoelement, i.e. 488 species (47.9 %), among them most of the Caucasian geoelements (326 species, 32 % of the total number of species and 66.8 % of boreal geoelements). In the second place are Old Mediterranean geoelements (290 species, 28.5 %), among them the largest number of species is rep-resented by Turan (48 species, 4.7 % of all species of flora xerophytes and 16.6 % of the ancient Medi-terranean geoelements). In the third place are tie geoelements (165 species, 16.2 %), where the largest number of species is represented by subcaucasian geoelements (68 species, 6.8 % of the entire flora and 41.8 % of binder geoelements). Common holarctic geoelements account for 70 species (6.9 %), Palaearctic dominates (57 spe-cies, 5.6 % of the entire flora and 81.4 from com-mon holarctic geoelements). Pluriregional geoelements and adventitious species represented a small amount (2 and 3 respectively). Consequent-ly, according to the predominant groups of studied geoelements the flora can be characterized as bo-real-Old Mediterranean binding.