Vincetoxicum rossicum, an invasive alien species in expansion near Oslo, Norway
Vincetoxicum rossicum (= Cynanchum rossicum – Asclepiadaceae) is a perennial vine originating from Ukraine and Southern European Russia around the Black Sea. It was introduced into Norway many years ago and is now considered invasive as it reduces biodiversity in nationally important habitats (fields, shores, forests) and threatens indigenous vegetation in calcareous areas around Oslo (e.g. islands of the inner Oslo fjord). The plant is also considered a threat in Canada and is prohibited in Connecticut, Massachusetts and New Hampshire (USA).
Sources
Bjereke K (2006) Vincetoxicum rossicum, an invasive species in expansion in Oslo, Norway. In: Neobiota. From Ecology to Conservation. 4th European Conference on Biological Invasions. Vienna (Austria), 2006-09-27/29, BfN-Skripten 184: page 80 (abst.).
Wisconsin Department of Natural Resources http://www.dnr.state.wi.us/invasives/fact/swallowwort_pale.htm
United State Department of Agriculture http://plants.usda.gov/java/profile?symbol=CYRO8