Page author: David Giblin
Fallopia japonica
Japanese knotweed
WTU specimens
Other herbaria
WTU images

Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.

Habitat: Riparian zones, roadsides, ditches, wastelots, and other disturbed open areas.

Flowers: June-September

Origin: Introduced from eastern Asia

Conservation Status: Not of concern

Description:

[none provided]


Accepted Name:
Fallopia japonica (Houtt.) Ronse Decr.
Publication: Bot. J. Linn. Soc. 98: 369. 1988.

Synonyms & Misapplications:
Polygonum cuspidatum Siebold & Zucc. [HC]
Polygonum cuspidatum Siebold & Zucc. var. compactum (Hook. f.) L.H. Bailey
Reynoutria japonica Houtt.
Infraspecies:
var. japonica – Japanese knotweed    Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.
Additional Resources:

PNW Herbaria: Specimen records of Fallopia japonica in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Fallopia japonica checklist entry.

E-Flora BC: Fallopia japonica atlas page.

CalPhotos: Fallopia japonica photos.

USDA Plants: Fallopia japonica information.

12 photographs:
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