Roadless Areas
Home/Species/ Douglas' Knotweed

Polygonum douglasii

Greene

Douglas' Knotweed

G5Secure Found in 29 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Identity
Unique IDELEMENT_GLOBAL.2.131629
Element CodePDPGN0L0X2
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderPolygonales
FamilyPolygonaceae
GenusPolygonum
Synonyms
Polygonum douglasii ssp. douglasiiPolygonum douglasii var. douglasii
Other Common Names
Douglas' knotweed (EN) Renouée de Douglas (FR)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic Comments
This record represents the narrow concept of Polygonum douglasii following FNA (vol. 5, 2005). FNA (vol. 5, 2005) elevates all of the varieties of Polygonum douglasii to full species. In contrast, Kartesz (1994) recognized Polygonum douglasii in a broad sense with seven subspecies distinguished (austiniae, douglasii, engelmannii, johnstonii, majus, nuttallii, spergulariiforme).
Conservation Status
Rank MethodExpertise without calculation
Review Date2016-06-27
Change Date2000-10-22
Edition Date1996-11-05
Edition AuthorsJean Gagnon (1996)
Ecology & Habitat
Other Nations (2)
United StatesN5
ProvinceRankNative
ArizonaSNRYes
New MexicoSNRYes
UtahSNRYes
IowaSNRYes
New YorkS1Yes
MichiganSNRYes
WyomingSNRYes
NevadaSNRYes
ColoradoS4Yes
CaliforniaSNRYes
VermontS2Yes
MontanaSNRYes
WashingtonSNRYes
IdahoSNRYes
MinnesotaSNRYes
West VirginiaSHYes
OregonSNRYes
New HampshireSNRYes
NebraskaS2Yes
CanadaN5
ProvinceRankNative
AlbertaSNRYes
Yukon TerritoryS1Yes
British ColumbiaS5Yes
SaskatchewanS4Yes
ManitobaS3Yes
New BrunswickS1Yes
QuebecSNRYes
OntarioSNRYes
Plant Characteristics
Economic Value (Genus)No
Roadless Areas (29)
California (13)
AreaForestAcres
Castle PeakTahoe National Forest14,974
Cub CreekLassen National Forest8,643
Domeland Add.Sequoia National Forest3,046
Elk CreekMendocino National Forest23,182
Granite ChiefTahoe National Forest6,546
Hall Natural AreaInyo National Forest5,236
Heart LakeLassen National Forest9,349
Long MeadowHumboldt-Toiyabe National Forest11,967
Middle YubaTahoe National Forest7,379
Mt. JacksonHumboldt-Toiyabe National Forest20,721
NightStanislaus National Forest3,173
SnoozerKlamath National Forest23,414
Sweetwater (CA)Humboldt-Toiyabe National Forest19,241
Colorado (1)
AreaForestAcres
Long ParkRoutt NF42,100
Oregon (5)
AreaForestAcres
Echo MountainWillamette National Forest8,098
Flag CreekMalheur National Forest7,716
French Pete (a)Willamette National Forest1,668
Snake RiverWallowa-Whitman National Forest31,229
South KalmiopsisSiskiyou National Forests104,477
Utah (5)
AreaForestAcres
AtchinsonDixie National Forest17,655
Clear CreekSawtooth National Forest7,188
MogotsuDixie National Forest16,762
Right Hand Fork LoganWasatch-Cache National Forest15,023
Temple PeakWasatch-Cache National Forest24,081
Washington (2)
AreaForestAcres
BackboneGifford Pinchot National Forest1,201
Long SwampOkanogan National Forest66,344
Wyoming (3)
AreaForestAcres
Grayback RidgeBridger-Teton National Forest295,113
Platte River AdditionMedicine Bow-Routt National Forest7,962
Savage Run AdditionMedicine Bow-Routt National Forest2,368
References (2)
  1. Flora of North America Editorial Committee (FNA). 2005. Flora of North America north of Mexico. Vol. 5. Magnoliophyta: Caryophyllidae: Caryophyllales, Polygonales, and Plumbaginales. Oxford Univ. Press, New York. vii + 656 pp.
  2. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.