Taxon  Report   11035 
Polygonum majus  (Meisn.) Piper
Large douglas' knotweed

Polygonum majus
© 2008 Keir Morse
Polygonum majus, a dicot, is an annual herb that is native to California and is also found outside of California, but is confined to western North America.

 Interactive Distribution Map 

 Observation Hotline 
 (observation details + photos)

point, line, or polygon

 Plant Characteristics
 and Associations

Bloom Period
Polygonum majus
© 2008 Keir Morse
Genus: Polygonum
Wetlands:Usually occurs in non wetlands, but occasionally found in wetlands [U.S. Fish & Wildlife Service.]
AFFINITY to serpentine soil:   1.5 (weak indicator)   [Safford et al 2005]
Distribution by County 

Add an Observation of  Polygonum majus

Name Status:
Accepted by TJM2
Alternate Names:
(according to)

TJM2: Polygonum douglasii ssp. majus
 More information about  Polygonum majus
Location Suitability

Nursery / seed vendor availability from CNPLX
Commercial availability unknown.


Photos on CalPhotos / Google Images

website references on Google

Jepson eFlora

Records from the Consortium of California Herbaria

Search (Flora of North America)

Search the Lady Bird Johnson Wildflower Center

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]. 2015. Berkeley, California: The Calflora Database [a non-profit organization].
Available:   (Accessed: Oct 09, 2015).

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

News About Calflora Home
Calflora  -  1700 Shattuck Avenue   #198,   Berkeley, CA   94709  -  510 883-3148  -  CONTACT