Washington Flora Checklist

A Checklist of the Vascular Plants of Washington State
Hosted by the University of Washington Herbarium, Burke Museum

Checklist » Polygonaceae » Fallopia japonica

Fallopia japonica (Houtt.) Ronse Decr.[FNA5, HC2]

itadori knotweed

Publication: Bot. J. Linn. Soc. 98: 369. 1988.

Origin: Introduced from eastern Asia

Herbarium search: CPNWH

Notes: An aggressive weed in lowland Washington, especially in riparian corridors.

Infraspecies:

var. japonica [FNA5, HC2]

Japanese knotweed

Last updated 5/13/2020 by David Giblin.

Synonyms & Misapplied Names:

Polygonum cuspidatum Siebold & Zucc.[HC]

Polygonum cuspidatum Siebold & Zucc. var. compactum (Hook. f.) L.H. Bailey

Reynoutria japonica Houtt.