When it was introduced to Europe in the mid-19th century as an ornamental plant, Japanese knotweed, known as Reynoutria japonica var japonica, quickly went rogue. Despite not being native to the British Isles, it was able to rapidly form self-sustaining colonies in the wild.
Today, this invasive plant is found across much of Britain and Ireland. It is often spotted growing in areas influenced by people such as waste ground, along riverbanks, roadsides and railway lines.
