Taxon  Report   6746 
Polygonum cuspidatum  Sieb. & Zucc.  (not an active name; please see Fallopia japonica)
Japanese knotweed
Polygonum cuspidatum
© 2006 Dr. Amadej Trnkoczy
CalPhotos: 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.
It is an invasive plant. The California Invasive Plant Council classifies its potential impact on native ecosystems as moderate - ALERT (plant profile / CalWeedMapper).

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
Family: POLYGONACEAE  
Genus: Polygonum
Community:
escaped cultivar
Wetlands:Usually occurs in non wetlands, but occasionally found in wetlands [U.S. Fish & Wildlife Service.]
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: 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)

USDA PLANTS Profile (POCU6)

Search the International Plants Names Index

Search efloras.org (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]. 2016. Berkeley, California: The Calflora Database [a non-profit organization].
Available: http://www.calflora.org/   (Accessed: May 26, 2016).

The information on this page comes from diverse sources. None of the links are sponsored.