Pistia stratiotes found in the delta of the Volga River (Russia)
Pistia stratiotes (Araceae, EPPO Alert List) was found in 1989 in the delta of the Volga River in Russia. Although it was considered that the species would not be able to establish there, it was found covering 5 km of the Volga River near Astrakhan the following year. The species was able to survive the harsh winters as hot water was released by a nearby electric power station. Pistia stratiotes has also been observed covering the Kutum River, and it is reported that dogs could cross the river by walking on the dense mats of the plant.
Pilipenko VN (1993) Pistia stratiotes (Araceae), a tropical species in the delta of the Volga river. Botanicheskii Zhurnal. Moscow & Leningrad 78, 119-120.