E-Flora BC: Electronic Atlas of the Flora of British Columbia

Persicaria minor (Hudson) Opiz
Asian knotweed
Polygonaceae (Buckwheat family)

Introduction to Vascular Plants

© Robert Flogaus-Faust  Email the photographer   (Photo ID #26323)

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Distribution of Persicaria minor
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Asian knotweed is an introduced species of wet, muddy shorelines in British Columbia that originates in Europe. It is found in southwestern BC (Fraser Valley) and south-central BC.

Species Information

Annual herb from a fibrous root; stems prostrate to ascending, several, simple or branched, 10-40 cm tall/long.
Basal leaves lacking; stem leaves alternate, linear to narrowly elliptic, the blades 3-10 cm long, 5-8 mm wide, the stalks short; stipules long coarse-hairy, the hairs extending about 1 mm beyond the tips.
Inflorescence of several flowers in spikelike racemes; perianths pink or purplish (rarely white), 1.5-3.5 mm long.
Achenes, 3-angled or lens-shaped, 2-2.5 mm long, black, smooth and shiny.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Wet, muddy shorelines in the lowland and steppe zones; infrequent in SW BC (lower Fraser Valley), rare in SC BC (Tranquille); introduced from Europe.

Source: The Illustrated Flora of British Columbia


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Polygonum minus Huds.

Taxonomic and Nomenclatural Links

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General References