Taxon  Report   11010 
Persicaria lapathifolia  (L.) Gray
Common knotweed
Persicaria lapathifolia
© 2008 Louis-M. Landry
Click on a photo to see it bigger.
Persicaria lapathifolia
© 2009 Phil Pullen
Persicaria lapathifolia
© 2005 Luigi Rignanese
Persicaria lapathifolia, a dicot, is an annual herb that is native to California and 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
Genus: Persicaria
(many plant communities), wetland-riparian
Wetlands: Occurs usually in wetlands, occasionally in non wetlands
Distribution by County 

Add an Observation of  Persicaria lapathifolia

Name Status:
Accepted by TJM2
PLANTS accepted name: Polygonum lapathifolium
Alternate Names:
(according to)

TJM2: Polygonum lapathifolium
More information about  Persicaria lapathifolia
Nursery / seed vendor availability from CNPLX
Commercial availability unknown.
Landscaping information from Calscape
Photos on CalPhotos / Google Images
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]. 2018. Berkeley, California: The Calflora Database [a non-profit organization].
Available:   (Accessed: Feb 24, 2018).

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