logo Calflora, a 501c3 non-profit
Taxon  Report  
Polygonum douglasii  Greene
Douglas' knotweed
Polygonum douglasii is an annual herb that is native to California, and also found elsewhere in North America and beyond.
Siskiyou Del Norte Modoc Humboldt Shasta Lassen Trinity Plumas Tehama Butte Mendocino Glenn Sierra Yuba Lake Nevada Colusa Placer Sutter El Dorado Yolo Alpine Napa Sonoma Sacramento Mono Amador Solano Calaveras Tuolumne San Joaquin Marin Contra Costa Alameda Santa Cruz Mariposa Madera San Francisco San Mateo Merced Fresno Stanislaus Santa Clara Inyo San Benito Tulare Kings Monterey San Bernardino San Luis Obispo Kern Santa Barbara Ventura Los Angeles Riverside Orange San Diego Imperial
bloom graphic
Bloom Period
Genus: Polygonum
Family: Polygonaceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Wetlands: Occurs usually in non wetlands, occasionally in wetlands

Habitat: meadows

Communities: Sagebrush Scrub, Yellow Pine Forest, Red Fir Forest, Lodgepole Forest, Subalpine Forest

Name Status:
Accepted by JEF + PLANTS
Alternate Names:
ICPNPolygonum buxiforme
JEFPolygonum douglasii ssp. douglasii
JEFPolygonum douglasii var. latifolium
JEFPolygonum emaciatum
JEFPolygonum montanum
Information about  Polygonum douglasii from other sources
Nursery availability from CNPLX
Commercial availability unknown.
Jepson eFlora

USDA PLANTS Profile (PODO4)

Photos on Calflora

Photos on CalPhotos

Google Images

Photos on iNaturalist

ID Tips on PlantID.net


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]. 2023. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 02/04/2023).