Calflora
Taxon  Report   11010    
Persicaria lapathifolia  (L.) Delarbe
Common knotweed
Persicaria lapathifolia
© 2008 Louis-M. Landry
Photos from
CalPhotos / Calflora
Persicaria lapathifolia
© 2009 Phil Pullen
Persicaria lapathifolia
© 2005 Luigi Rignanese
Persicaria lapathifolia, a dicot, is an annual herb that is native to California, is also found elsewhere in North America and beyond.

Interactive Distribution Map


Observation Hotline
(observation details + photos)



point, line, or polygon

Plant Characteristics
and Associations



Bloom Period
Persicaria lapathifolia
© 2008 Louis-M. Landry
Family: POLYGONACEAE  
Genus: Persicaria
Communities: (many plant communities), wetland-riparian

Wetlands: Occurs usually in wetlands, occasionally in non wetlands

Name Status:
Accepted by JEF

PLANTS accepted name:
Polygonum lapathifolium

Alternate Names:
ICPN: Polygonum lapathifolium
More information about  Persicaria lapathifolia
Nursery / seed vendor availability from CNPLX
Commercial availability unknown.
Landscaping information from Calscape
Photos on PlantID.net   /   Google Images
Jepson eFlora

Records from the Consortium of California Herbaria

USDA PLANTS Profile (POLA4)

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]. 2018. Berkeley, California: The Calflora Database [a non-profit organization].
Available: https://www.calflora.org/   (Accessed: Nov 17, 2018).

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