Sosnowsky's hogweed (Heracleum sosnowskyi Manden., Apiaceae) in Bashkortostan.
Heracleum sosnowskyi Manden. grows mainly in the northern and central Cis-Urals in the Republic of Bashkortostan; in total, 22 localities are known. In the case of naturalization, the species becomes dominant and forms communities of the Urtico dioicae-Heracleetum sosnowskyi association. Five cenopopulations of H. sosnowskyi were studied in 2016-2019 in the Krasnokamsky, Tatyshlinsky, and Yanaulsky districts of Bashkortostan. The total density of the species in these cenopopulations is high (41-92 plants/m2), and the effective density (density of generative individuals) is 1.9-3.4 plants/m2. The biomass can reach 2.3-4.6 kg/m2. The share of the species in the community is high (77.8-96.8%). According to the majority of parameters of both vegetative and generative spheres, the cenopopulation located near the village of Tashkinovo takes the leading position, whereas the minimum values of all parameters are registered for the cenopopulation located near the village of Razdolye in the Krasnokamsky district. H. sosnowskyi poses a serious threat to the ecosystem biodiversity in the Republic of Bashkortostan.