Taxon  Report   6734    
Polygonum amphibium  L.  
(no longer an active name)
Swamp knotweed,  Water knotweed, Water smartweed
Polygonum amphibium, a dicot, is a perennial herb that is native to California, is also found elsewhere in North America and beyond.

Bloom Period
Genus: Polygonum
Communities: Yellow Pine Forest, Red Fir Forest, Lodgepole Forest, Subalpine Forest, Foothill Woodland, Chaparral, Valley Grassland, (many plant communities), wetland-riparian
Name Status:
Accepted by PLANTS

ICPN other name:
Persicaria amphibia

NOTE: Polygonum amphibium is no longer an active name.
More information about  Polygonum amphibium
Nursery availability from CNPLX
This plant is available commercially.
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]. 2019. Berkeley, California: The Calflora Database [a non-profit organization]. Available:   (Accessed: Oct 15, 2019).