The biology of Canadian weeds. 65. Salsola pestifer A. Nels.
In Canada, Russian thistle (Salsola pestifer) occurs in disturbed habitats in every province except Newfoundland. A key that separates 3 other closely related species, S. kali, S. collina and S. paulsenii, is provided, and the weed status of these 3 species in Canada or the USA is discussed. The biology of S. pestifer, the most common weedy species in the genus, is reviewed, notes being included on insects, microorganisms and viruses that have been recorded on S. pestifer in North America, and on the release in Saskatchewan of Coleophora parthenica and C. klimeschiella (from the USA) as biological control agents against S. pestifer.