Taxon  Report   10891    
Fallopia japonica  (Houtt.) Ronse Decr.
Japanese knotweed
Fallopia japonica, a dicot, is a perennial herb that is not native to California. Cal-IPC rating: Moderate
Observation Search
(360 records)
one or more occurrences
within a 7.5-minute quadrangle

Bloom Period
Genus: Fallopia
Wetlands: Occurs usually in non wetlands, occasionally in wetlands
Name Status:
Accepted by ICPN

PLANTS other name:
Polygonum cuspidatum

Alternate Names:
ICPN: Fallopia japonica var. japonica
ICPN: Polygonum cuspidatum
More information about  Fallopia japonica
Search (Flora of North America)

Photos on   /   Google Images

Consortium of California Herbaria

USFS Fire Effects Information System:  Three Asian Knotweeds

The Spruce landscaping journal:  Overview of Control Methods.

USDA Species Profile:  Japanese Knotweed Resources

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. [web application]. 2020. Berkeley, California: The Calflora Database [a non-profit organization]. Available:   (Accessed: Jan 25, 2020).