Japanese knotweed can grow more than a metre a month and is famed for pushing through tarmac, concrete and drains. Its effect on native species is often devastating as it out-competes indigenous species covering large tracts of land to the exclusion of the native flora and associated fauna.
It was brought to Britain from Japan as an ornamental garden plant in the mid-nineteenth century. However, over time it has become widespread in a range of habitats, particularly roadsides, riverbanks and derelict land where it causes serious problems by displacing native flora and causing structural damage.
Due to its vigorous nature and the damage it causes it is one of only two terrestrial plants listed as illegal to cause it to grow in the wild.
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