Calflora
Taxon  Report   11035    
Polygonum majus  (Meisn.) Piper
Large douglas' knotweed
Polygonum majus, a dicot, is an annual herb that is native to California, is also found outside of California, but is confined to western North America.
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 Period
Family: POLYGONACEAE  
Genus: Polygonum

Wetlands: Occurs usually in non wetlands, occasionally in wetlands

Ultramafic affinity: 1.5; (weak indicator)

Name Status:
Accepted by JEF

PLANTS other name:
Polygonum douglasii ssp. majus

Alternate Names:
JEF: Polygonum douglasii ssp. majus
More information about  Polygonum majus
Search efloras.org (Flora of North America)

Landscape information from Calscape

Photos on PlantID.net   /   Google Images

Consortium of California Herbaria 2


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]. 2020. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: Sep 25, 2020).