Taxon  Report   11015 
Persicaria wallichii  Greuter & Burdet
Himalayan knotweed
Persicaria wallichii
© 2015 Phil Pullen
More photos from
CalPhotos / Calflora
Persicaria wallichii
© 2015 Phil Pullen
Persicaria wallichii
© 2001 CDFA
Persicaria wallichii, a dicot, is a perennial herb that is not native to California; it was introduced from elsewhere and naturalized in the wild. There is a high risk of this plant becoming invasive in California according to Cal-IPC.

Interactive Distribution Map

Observation Hotline
(observation details + photos)

point, line, or polygon

one or more occurrences
within a 7.5-minute quadrangle

Plant Characteristics
and Associations

Bloom Period
Persicaria wallichii
© 2001 CDFA
Genus: Persicaria
weed, characteristic of disturbed places, wetland-riparian
Habitat: disturbed
Wetlands: Equally likely to occur in wetlands and non wetlands
Distribution by County 

Add an Observation of  Persicaria wallichii

Name Status:
Accepted by JEF
PLANTS accepted name: Polygonum polystachyum
Alternate Names:
(according to)

ICPN: Polygonum polystachyum
ICPN: Persicaria wallichii var. wallichii
More information about  Persicaria wallichii
Photos on CalPhotos / Google Images
Jepson eFlora

Records from the Consortium of California Herbaria

Search (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:   (Accessed: Jul 19, 2018).

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