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Potamogeton praelongus

Wulfen

White-stem Pondweed

G5Secure Found in 12 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.155381
Element CodePMPOT030V0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderNajadales
FamilyPotamogetonaceae
GenusPotamogeton
Other Common Names
Potamot à longs pédoncules (FR) whitestem pondweed (EN)
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.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-07-09
Change Date1984-06-25
Edition Date2025-07-09
Edition AuthorsN. Ventrella (2025)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Potamogeton praelongus is an aquatic perennial pondweed occurring in lakes, ponds, bogs, streams, rivers, and reservoirs of North America, Greenland, and Eurasia. In North America it is found from Alaska east to Newfoundland south to California, Utah and Colorado, Indiana, and New Jersey in the United States and Canada. There are several thousand estimated occurrences of this taxon rangewide, which are threatened in North America by aquatic herbicides, eutrophication, invasive species, recreation, alteration of hydrology, grazing by carp, and likely other threats in some places. Little is known about trends or threats rangewide, but with a large range extent, high number of occurrences, abundant habitat, and broad habitat preferences, Potamogeton praelongus is considered secure.
Range Extent Comments
Potamogeton praelongus is a circumboreal species, occurring in North America, Greenland, and Eurasia (FNA 2000, POWO 2025). In North America it is found from Alaska east to Newfoundland south to California, Utah, Colorado, Indiana, and New Jersey in the United States and Canada (FNA 2000). Range extent was estimated to be 90 million square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are thousands of occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, Potamogeton praelongus is threatened in North America by aquatic herbicides, eutrophication, invasive species, recreation, alteration of hydrology, grazing by non-native carp, and likely other threats in some places (NatureServe 2025)
Ecology & Habitat

Habitat

Potamogeton praelongus occurs in a wide range of freshwater environments, including bogs, lakes, ponds, rivers, streams, and reservoirs up to elevations of 3231 m, typically in full sun and deeper waters (optimal depth is around 2.5 m, with a range of 0.1–7.0 m) (Les 2020).
Palustrine Habitats
Bog/fen
Other Nations (2)
CanadaN5
ProvinceRankNative
OntarioS4Yes
SaskatchewanS4Yes
Island of NewfoundlandS3Yes
Nova ScotiaS3Yes
AlbertaS4Yes
NunavutSUYes
British ColumbiaS5Yes
ManitobaS4Yes
Northwest TerritoriesS4Yes
New BrunswickS3Yes
Yukon TerritoryS4Yes
Prince Edward IslandS4Yes
QuebecS4Yes
LabradorS3Yes
United StatesN5
ProvinceRankNative
OhioS1Yes
MassachusettsSNRYes
PennsylvaniaS1Yes
South DakotaSNRYes
UtahSNRYes
MontanaSNRYes
VermontS4Yes
IowaS1Yes
OregonS2Yes
ColoradoS2Yes
New YorkS5Yes
New HampshireSHYes
NebraskaS1Yes
WisconsinSNRYes
ConnecticutSNRYes
MaineSNRYes
North DakotaS1Yes
AlaskaSNRYes
MichiganSNRYes
IndianaS1Yes
CaliforniaS2Yes
New JerseyS1Yes
IllinoisS1Yes
IdahoSNRYes
MinnesotaSNRYes
WyomingS2Yes
WashingtonSNRYes
Threat Assessments
ThreatScopeSeverityTiming
6 - Human intrusions & disturbanceUnknownUnknownUnknown
6.1 - Recreational activitiesUnknownUnknownUnknown
8 - Invasive & other problematic species, genes & diseasesUnknownUnknownUnknown
8.1 - Invasive non-native/alien species/diseasesUnknownUnknownUnknown
8.1.1 - Unspecified speciesUnknownUnknownUnknown
9 - PollutionUnknownUnknownUnknown
9.3 - Agricultural & forestry effluentsUnknownUnknownUnknown
9.3.1 - Nutrient loadsUnknownUnknownUnknown
9.3.3 - Herbicides and pesticidesUnknownUnknownUnknown

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (12)
California (5)
AreaForestAcres
Hoover - Green Ck NoHumboldt-Toiyabe National Forest7,155
Mt. EddyShasta-Trinity National Forest7,232
ProspectLassen National Forest4,078
Robinson PeakHumboldt-Toiyabe National Forest5,835
Trail LakeLassen National Forest1,124
Oregon (3)
AreaForestAcres
Lake ForkWallowa-Whitman National Forest21,936
Mt. BaileyUmpqua National Forest18,401
Sky Lakes AWinema National Forest3,940
Utah (1)
AreaForestAcres
Temple PeakWasatch-Cache National Forest24,081
Vermont (1)
AreaForestAcres
Griffith Lake 09084Green Mountain and Finger Lakes National Forests1,833
Wyoming (2)
AreaForestAcres
Libby FlatsMedicine Bow-Routt National Forest11,107
Snowy RangeMedicine Bow-Routt National Forest29,660
References (9)
  1. Flora of North America Editorial Committee (FNA). 2000. Flora of North America north of Mexico. Vol. 22. Magnoliophyta: Alismatidae, Arecidae, Commelinidae (in part), and Zingiberidae. Oxford Univ. Press, New York. xxiii + 352 pp.
  2. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  3. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  4. 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.
  5. Les, D. 2020. Aquatic Monocotyledons of North America: Ecology, Life History, and Systematics. CRC Press, Boca Raton, FL. 568 pp.
  6. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  7. Plants of the World Online (POWO). 2025. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Online. Available: https://powo.science.kew.org/ (accessed 2025).
  8. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  9. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).