Taxon  Report   6752    
Polygonum douglasii  Greene  ssp. majus  (Meisn.) J. C. Hickman  
(no longer an active name)
Large douglas' knotweed,  Large knotweed
Polygonum douglasii ssp. majus, a dicot, is an annual herb that is native to California, is also found outside of California, but is confined to western North America.

Bloom Period
Genus: Polygonum
Parent: Polygonum douglasii
Wetlands: Occurs usually in non wetlands, occasionally in wetlands
Name Status:
Accepted by PLANTS

JEF other name:
Polygonum majus

Alternate Names:
PLANTS: Polygonum coarctatum var. majus
PLANTS: Polygonum majus
NOTE: Polygonum douglasii ssp. majus is no longer an active name.
More information about  Polygonum douglasii ssp. majus
Nursery availability from CNPLX
Commercial availability unknown.
Jepson eFlora


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]. 2020. Berkeley, California: The Calflora Database [a non-profit organization]. Available:   (Accessed: Jun 05, 2020).