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Plant Database

Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

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Polygonum douglasii ssp. majus

Polygonum douglasii Greene ssp. majus (Meisn.) J.C. Hickman

Large Douglas' Knotweed, Large Knotweed, Wiry Knotweed

Polygonaceae (Buckwheat family)

Synonym(s): Polygonum coarctatum var. majus, Polygonum majus

USDA Symbol: PODOM2

USDA Native Status: L48 (N), CAN (N)

 

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Plant Characteristics

Duration: Annual
Habit: Herb
Fruit Type: Achene
Size Notes: Up to about 2 feet tall.

Bloom Information

Bloom Color: White , Pink
Bloom Time: May , Jun , Jul , Aug , Sep

Distribution

USA: CA , ID , MT , NV , OR , WA , WY
Canada: BC
Native Habitat: Dry plains, meadows, sometimes on serpentine.

National Wetland Indicator Status

Region:AGCPAKAWCBEMPGPHIMWNCNEWMVE
Status: FACU FACU
This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

Web Reference

Webref 30 - Calflora (2018) Calflora
Webref 3 - Flora of North America (2014) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

USDA: Find Polygonum douglasii ssp. majus in USDA Plants
FNA: Find Polygonum douglasii ssp. majus in the Flora of North America (if available)
Google: Search Google for Polygonum douglasii ssp. majus

Metadata

Record Modified: 2020-11-12
Research By: CBR

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