Buddleia

This lovely purple Buddleia (Buddleja davidii) seen here in a hay meadow, is viewed by the Department for the Environment, Food and Rural Affairs (Defra) as an invasive non-native species. Its "invasion history" has been charted from its introduction to the UK in the 1800s from China to the first record of the plant in the wild in 1922. (further infomation)