Materials on the distribution of plant species which are rare for the Volgograd oblast

Russia Abstract. The information about the distribution of 28 rare and endangered species of vascular plants under Federal and regional security, registered in 2018 on the territory of the Volgograd oblast under the Federal and regional security is given. Among them, 2 species ( Crambe tataria Sebeók и Stipa zalesskii Wilensky ex P. A. Smirn.) are included in the List of Threatened plant species of Europe. Each location is linked to the grid of Atlas Flora Europaea. The obtained materials about the distribution of rare and endangered species of vascular plants represent an important data for long-term monitoring and also for environmental management measures at the regional


Introduction
Volgograd oblast is located in the South-East of the European part of Russia in the basins of the Lower Volga and the Middle Don. The majority of this region belongs to the steppe zone. Zonal vegetation is herb-bunchgrass (moderately arid) and bunchgrass (dry) steppes, which are now replaced by half-shrub-bunchgrass desert steppe to the East and South-East. Only small area in the North-West belongs to the forest-steppe zone.
This region has high, unique for lowlands vascular plant diversity: more than 2970 species were registered there [1]. In this regard, information on the distribution of rare and threatened with extinction species is valuable from a scientific and environmental point of view. The present work provides new information, specifying the distribution of some vascular plants under the protection at the regional and Federal levels.
The nomenclature and volume of taxa are mainly standardized by "The Euro+Med PlantBase" [6]. Abbreviations of taxa authors are given according to "International Plant Name Index" [7].
The geographical coordinates are given in WGS 84 system when quoting labels. The number of the square is indicated in brackets in Atlas Flora Europaea [8]. Collected herbarium specimens are stored in PVB; doublets are transferred to MW and NS.

Results
The studies revealed 565 species of vascular plants [9], 19 species of which are included in the Red Book of the Russian Federation [10], 28 species are in the Red Book of Volgograd oblast [1] and 2 species are in the List of European Red List of Vascular Plants [11].
Data on findings of rare vascular plants are presented below. Collection of vascular plants and the species inside are listed in order of the Latin alphabet. * -species listed in the Red Book of the Russian Federation [10].

Discussion
As a result of the research, 13 localities of 28 species of vascular plants, listed in the Red Book of Volgograd oblast [1] were identified, 19 species of which are included in the Red Book of the Russian Federation [10] and 2 species are in the European Red List of vascular plants [11]. Most of the detected species is confined in its distribution to the chalk and marl-chalk outcrops. Each location is linked to the grid of Atlas Flora Europaea.
The obtained materials on the distribution of rare and threatened species of vascular plants are the important data for long-term monitoring, as well as for environmental measures at the regional level.