Common names:
Japanese knotweed, Asian knotweed
Family:
Scientific name:
Reynoutria japonica
Synonym:
Fallopia japonica
Main flower color:
Range:
Most of the British Isles; absent only from the Scottish Highlands. An invasive species
Height:
Up to 2 m
Habitat:
Waste ground, roadsides, pathways
Flowers:
Greenish-white, with six tepals and six stamens. The three outer tepals are larger, and have a broad keel. Flowers form in dense, arching clusters, often hanging downwards
Fruit:
Brownish nuts, initially flanked by three wings, green at the base otherwise white
Leaves:
Hairless, triangular to ovate, with flat bases and pointed tips; on much-branched, reddish stems. Up to 12 cm long
Season:
August to October
Rarity:
★★★★★
