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Reynoutria japonica
Also called Mexican Bamboo, Asian Knotweed, Asiatic Knotweed, Itadori Knotweed, Japanese Fleece Flower, Donkey Rhubarb, Fleeceflower
Japanese knotweed is a fast-growing, hollow-stemmed herbaceous perennial from East Asia, and this entry describes the species Reynoutria japonica. Its key trait is extreme vigour: it spreads by rhizomes and is invasive in many countries, so it should be contained rather than planted.
Reynoutria japonica, synonyms Fallopia japonica and Polygonum cuspidatum, is a species of herbaceous perennial plant in the knotweed and buckwheat family Polygonaceae. Common names include Japanese knotweed and Asian knotweed. It is native to East Asia in Japan, China and Korea. In North America and Europe, the species has successfully established itself in numerous habitats; it is classified as a pest and invasive species in several countries. The plant is popular with beekeepers and its young stems are edible, making it an increasingly popular foraged vegetable with a flavour described as lemony rhubarb.
It is native to East Asia in Japan, China and Korea. In this range, R. japonica propagates both sexually and vegetatively. In North America and Europe, the species has successfully established itself in numerous habitats, and is classified as a pest and invasive species in several countries. Spread in invaded ranges is mainly vegetative, through rhizome pieces, stem fragments and soil contaminated with plant material; waterways, construction activity and garden waste can move these propagules over longer distances. Many introduced populations are dominated by male-sterile clonal plants, but some set seed or hybridise with giant knotweed, producing Bohemian knotweed, which bears viable seed.
Japanese knotweed flowers are valued by some beekeepers as an important source of nectar for honeybees, at a time of year when little else is flowering. Japanese knotweed yields a monofloral honey, usually called bamboo honey by northeastern U.S. beekeepers, like a mild-flavored version of buckwheat honey (a related plant also in the Polygonaceae).
Text excerpted from the Wikipedia article Reynoutria japonica by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.
