Taxon  Report   10891 
Fallopia japonica  (Houtt.) Ronse Decr.
Japanese knotweed
Fallopia japonica
© 2005 Louis-M. Landry
CalPhotos: click on a
photo to see it bigger
Fallopia japonica
© 2011 Louis-M. Landry
Fallopia japonica, a dicot, is a perennial herb that is not native to California.
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



Bloom Period
Fallopia japonica
© 2006 Dr. Amadej Trnkoczy
Family: POLYGONACEAE  
Genus: Fallopia
Community:
escaped cultivar
Wetlands:Usually occurs in non wetlands, but occasionally found in wetlands [U.S. Fish & Wildlife Service.]
Name Status:
Accepted by TJM2
Alternate Names:
(according to)

TJM2: Polygonum cuspidatum
TJM2: Reynoutria japonica
More information about  Fallopia japonica
Photos on CalPhotos / Google Images

Jepson eFlora

Records from the Consortium of California Herbaria

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: Feb 06, 2016).

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