First Find of Ambrosia trifida L. (Asteraceae) in Western Siberia

A dangerous invasive species Ambrosia trifida L. (Asteraceae) was found in Western Siberia in Tyumen (Tyumen Region, Russia) for the first time in August 2024. This species is included in the list of the 100 most aggressive alien species in Russia and in the list of the 100 most dangerous invasive species in Europe. Information on the locality of the species, the supposed vector of invasion, and the species composition of the community is presented.