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Potamogeton nodosus

Poir.

Longleaf Pondweed

G5Secure Found in 5 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.154230
Element CodePMPOT030P0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderNajadales
FamilyPotamogetonaceae
GenusPotamogeton
Other Common Names
longleaf pondweed (EN) Long-leaved Pondweed (EN) Potamot noueux (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.
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 nodosus is an aquatic perennial pondweed occurring in lakes streams, rivers, and sloughs nearly worldwide, in North America, the West Indies, Central America, South America, Africa, and Eurasia. There are several thousand estimated occurrences of this taxon rangewide, which are threatened in North America by the alteration of hydrology, flooding, recreation, invasive species, 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 nodosus is considered secure.
Range Extent Comments
Potamogeton nodosus occurs nearly worldwide, in North America, the West Indies, Central America, South America, Africa, and Eurasia (FNA 2000, POWO 2025). In North America, it is found from British Columbia east to Nova Scotia (excluding Manitoba), Canada, south throughout the entire United States. Range extent was estimated to be over 152 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 several thousand occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, Potamogeton nodosus is threatened in North America by the alteration of hydrology, flooding, recreation, invasive species, and likely other threats in some places (NatureServe 2025). There is insufficient data, including anecdotal accounts, to understand the scope and severity of threats for this taxon.
Ecology & Habitat

Habitat

Potamogeton nodosus occurs in "clear to turbid waters of lakes, streams, rivers, and sloughs" from 0-3300 m in elevation (FNA 2000). It is found a wide range of freshwater to slightly brackish habitats at water depths from 10 cm to 2.1 m and prefers alkaline waters (pH 6.3–9.5) (Les 2020).

Reproduction

Potamogeton nodosus has high seed output (up to 11,800 fruits/5.9 m²), with seeds dispersed by water and waterfowl (Les 2020).
Palustrine Habitats
HERBACEOUS WETLANDFORESTED WETLAND
Other Nations (2)
United StatesN5
ProvinceRankNative
WashingtonSNRYes
NebraskaSNRYes
South DakotaSNRYes
OregonSNRYes
IowaS4Yes
DelawareS4Yes
MontanaSNRYes
IndianaSNRYes
New HampshireS2Yes
AlabamaSNRYes
WisconsinSNRYes
MarylandSNRYes
LouisianaSNRYes
IdahoSNRYes
ArkansasSNRYes
KansasS4Yes
TexasSNRYes
Rhode IslandSNRYes
MissouriSNRYes
MississippiSNRYes
MassachusettsSNRYes
ConnecticutSNRYes
MinnesotaSNRYes
NevadaS2Yes
New JerseyS3Yes
IllinoisS3Yes
FloridaSNRYes
MichiganSNRYes
New YorkS5Yes
TennesseeSNRYes
North DakotaSNRYes
North CarolinaS1Yes
ColoradoS3Yes
VirginiaS4Yes
ArizonaSNRYes
OhioSNRYes
VermontS4Yes
West VirginiaS4Yes
CaliforniaSNRYes
HawaiiSNRYes
GeorgiaSNRYes
District of ColumbiaSNRYes
New MexicoSNRYes
PennsylvaniaSNRYes
UtahSNRYes
MaineSNRYes
South CarolinaS1Yes
KentuckyS3Yes
OklahomaSNRYes
WyomingS1Yes
CanadaN5
ProvinceRankNative
Nova ScotiaS1Yes
QuebecS3Yes
OntarioS5Yes
New BrunswickS1Yes
SaskatchewanS1Yes
AlbertaS1Yes
British ColumbiaS4Yes
Threat Assessments
ThreatScopeSeverityTiming
6 - Human intrusions & disturbanceUnknownUnknownUnknown
6.1 - Recreational activitiesUnknownUnknownUnknown
7 - Natural system modificationsUnknownUnknownUnknown
7.2 - Dams & water management/useUnknownUnknownUnknown
8 - Invasive & other problematic species, genes & diseasesUnknownUnknownUnknown
8.1 - Invasive non-native/alien species/diseasesUnknownUnknownUnknown
8.1.1 - Unspecified speciesUnknownUnknownUnknown
11 - Climate change & severe weatherUnknownUnknownUnknown
11.4 - Storms & floodingUnknownUnknownUnknown

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (5)
California (3)
AreaForestAcres
Eagle PeakCleveland National Forest6,481
No NameCleveland National Forest4,897
SugarloafSan Bernardino National Forest8,206
Vermont (1)
AreaForestAcres
Wilder Mountain 09082Green Mountain and Finger Lakes National Forests8,759
Virginia (1)
AreaForestAcres
Seng MountainJefferson National Forest6,428
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).