Taxon  Report   11035 
Polygonum majus  (Meisn.) Piper
Large douglas' knotweed
Polygonum majus
© 2008 Keir Morse
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Polygonum majus
© 2008 Keir Morse
Polygonum majus
© 2009 Neal Kramer
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.

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

TJM2: Polygonum douglasii ssp. majus
More information about  Polygonum majus
Jepson eFlora

Records from the Consortium of California Herbaria


Search (Flora of North America)

Search the Lady Bird Johnson Wildflower Center

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:   (Accessed: Oct 23, 2016).

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