More than 1700 species of vascular plants are known in the flora of Penza region, including alien fraction with about 400 species, 25 species of these being classified by us as the most dangerous invasive plants for ecosystems and public health in the region. These dangerous species are recommended for inclusion in the Black Book of the Penza region and the Black Book of the Volga Basin.
V.M. Vasjukov , L.A. Novikova