Taxon  Report   6746 
Polygonum cuspidatum  Sieb. & Zucc.  (not an active name; please see Fallopia japonica)
Japanese knotweed
Polygonum cuspidatum
© 2006 Dr. Amadej Trnkoczy
Click on a photo to see it bigger.
Polygonum cuspidatum, a dicot, is a perennial herb that is not native to California; it was introduced from elsewhere and naturalized in the wild. Cal-IPC rating: moderate

Interactive Distribution Map

Observation Hotline
(observation details + photos)

point, line, or polygon

one or more occurrences
within a 7.5-minute quadrangle

Plant Characteristics
and Associations
Polygonum cuspidatum
© 2005 Louis-M. Landry
Genus: Polygonum
escaped cultivar
Distribution by County 

Add an Observation of  Polygonum cuspidatum

Name Status:
Accepted by PLANTS + JM93
TJM2 accepted name: Fallopia japonica
Alternate Names:
(according to)

PLANTS: Fallopia japonica
PLANTS: Pleuropterus cuspidatus
PLANTS: Pleuropterus zuccarinii
PLANTS: Polygonum cuspidatum var. compactum
PLANTS: Polygonum zuccarinii
PLANTS: Reynoutria japonica
NOTE: Polygonum cuspidatum is not an active name in the Calflora species table.
More information about  Polygonum cuspidatum
Photos on CalPhotos / Google Images

Records from the Consortium of California Herbaria

Original Publication citation (ITIS)


Search the International Plants Names Index

Search (Flora of North America)

website references from Google

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]. 2018. Berkeley, California: The Calflora Database [a non-profit organization].
Available:   (Accessed: Jan 20, 2018).

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