''Koenigia weyrichii'' (

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

''Persicaria weyrichii''), the Chinese knotweed or Weyrich's knotweed, is a large, perennial,

rhizomatous In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

herb Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances. Culinary use typically distingu ...

native to

East Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Ja ...

. It is one of the parents of the cultivated hybrid ''Koenigia'' × ''fennica'', the other being ''

Koenigia alpina ''Koenigia alpina'' (synonym ''Aconogonon alpinum''), commonly known as alpine knotweed, is similar to '' Koenigia alaskana'', but differs in leaf size and achene An achene (; ), also sometimes called akene and occasionally achenium or achenoc ...

''.

References

Online Atlas of the British & Irish Flora entry
Polygonoideae {{Polygonaceae-stub