Japanese knotweed ((Fallopia japonica)) was introduced to Britain in the 19th century as an ornamental plant, and won a gold medal at a prestigious flower show under its previous name of (Polygonum cuspidatum). However, once planted, this knotweed spread and refused to go away. Beyond the Far East, its homeland, Japanese knotweed has no natural biological enemies to check its spread. On the other hand, in Japan, at least 30 species of insect and 6 species of fungi live on the plant and restrict its spread. In 2004, a UK government review of non-native species stated the costs involved in eradication would be at least GBP1.56bn. Some other ecology-related photographs: . Aggression | Environment | Nature | Horizontal | Outdoors