Synopsis of alien plants of the Middle Volga region

For the first time, a list of alien plants registered on the territory of the Middle Volga Region (within the boundaries of Samara and Ulyanovsk Regions) is published. The alien flora of the Middle Volga Region is represented by 461 species of vascular plants belonging to 275 genera and 77 families (23.1% of the total flora). For each species information is provided about the time of occurrence in the flora (archaeophyte, neophyte), mode of introduction (xenophyte, ergasiophygophyte), invasive status (ephemerophyte, colonophyte, epecophyte, agriophyte), life form, geographical element, frequency of occurrence, range of occupied habitats, as well as the date of first mention. The predominance of neophytes (394 species, 85.5%) over archaeophytes (67 species, 14.5%) was found in the alien flora of the Middle Volga region. For the first time, information is provided on the findings of such species as Cleome spinosa , Echinacea purpurea , Grindelia squarrosa , Jovibarba globifera , Phaseolus vulgaris , and Rudbeckia laciniata . All listed species are accompanied by comments. Among alien plants is dominated by epecophytes (149 species, 32.3%) and ephemerophytes (148 species, 32.1%), 142 species are colonophytes (30.8%) and 22 (4.8%) are agriophytes. 21 species belong to the disappeared ones, they are listed in the general list, but are not included in the analysis. Currently, there is a high rate of adventization of the regional flora - 161 species (35.0% of their total number) recorded in the last 20 years. According to the modes of introduction, alien species are distributed almost equally - 227 xenophytes (49.2%) and 234 ergasiophygophytes (50.8%). The most common alien species in the region have been identified. The results of distribution of alien species are presented by habitat types.