Buddleia (Buddleja davidii) which originated in China, 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 to the first record of the plant in the wild in 1922.
It is commonly found throughout the United Kingdom and is often seen along railway tracks, urban wastelands and roadsides
The plant can cause damage to buildings, such as crumbling brickwork - its tiny wind-blown seeds can germinate in decaying mortar.
And the problems caused by buddleia to the management of the rail network are described by the Non-Native Species Secretariat as "significant"