Potamogeton zosteriformis

Fern.

Flatstem Pondweed

G5Secure Found in 2 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.137985
Element CodePMPOT03160
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
flatstem pondweed (EN) Potamot zostériforme (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 Date2024-10-03
Change Date1984-06-25
Edition Date2024-10-03
Edition AuthorsN. Ventrella (2024)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Potamogeton zosteriformis is a perennial aquatic forb occurring in backwaters, bays, rivers, lakes, marshes, ponds, streams, and washes of North America from Alaska and the Northwest Territories south to California, east to New Jersey, and north to Newfoundland and Labrador in the United States and Canada. There are over 500 occurrences of this taxon, which are threatened by threatened by invasive species, aquatic herbicides, recreation, eutrophication, alteration of hydrology, development, and other threats in some places. Little is known about threats or trends, but with a large range extent, high number of occurrences, abundant habitat, broad habitat preferences, and no obvious intrinsic vulnerabilities, Potamogeton zosteriformis is considered secure.
Range Extent Comments
Potamogeton zosteriformis occurs in North America from Alaska and the Northwest Territories south to California, east to New Jersey, and north to Newfoundland and Labrador in the United States and Canada (FNA 2000). Range extent was estimated to be over 10 million square kilometers using herbarium specimens and photo-based observations documented between 1993 and 2024 (GBIF 2024, iNaturalist 2024, SEINet 2024).
Occurrences Comments
By applying a 1 km separation distance to herbarium records and photo-based observations documented between 1993 and 2024, there are estimated to be over 500 occurrences rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024).
Threat Impact Comments
Although threats are not widely documented, Potamogeton zosteriformis is threatened by invasive species, aquatic herbicides, recreation, eutrophication, alteration of hydrology, development, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species (NatureServe 2024).
Ecology & Habitat

Habitat

Potamogeton zosteriformis occurs in "backwaters (floodplain), bays (river), bottoms (river), channels (calcareous), depressions (meadow, organic), gravel pits, impoundments, inlets (shallow), lagoons, lakes (boggy, fen, glacial), marshes (deepwater, meadow, open, outwash), oxbows, ponds (beaver, stock), pools, potholes (permanent, sand prairie), rivers, shores (lake), sloughs, streams (slow), and washes at elevations to 2713 m" (Les 2020). It prefers clear, alkaline, calcereous waters in full-sun exposures.
Palustrine Habitats
HERBACEOUS WETLAND
Other Nations (2)
United StatesN5
ProvinceRankNative
AlaskaSNRYes
New JerseyS1Yes
NebraskaSNRYes
MassachusettsSNRYes
New HampshireS1Yes
MinnesotaSNRYes
South DakotaSNRYes
NevadaSNRYes
WisconsinSNRYes
CaliforniaS3Yes
UtahS1Yes
MarylandS1Yes
MontanaSNRYes
VermontS4Yes
ConnecticutSNRYes
West VirginiaSHYes
MaineSNRYes
WashingtonSNRYes
New YorkS5Yes
North DakotaSNRYes
VirginiaS1Yes
OhioS3Yes
IndianaSNRYes
PennsylvaniaS2Yes
IdahoSNRYes
OregonSNRYes
IowaS3Yes
MichiganSNRYes
WyomingS1Yes
IllinoisS3Yes
KansasSHYes
CanadaN5
ProvinceRankNative
QuebecS4Yes
Prince Edward IslandS1Yes
British ColumbiaS5Yes
Nova ScotiaS3Yes
AlbertaS4Yes
Northwest TerritoriesS4Yes
Island of NewfoundlandS1Yes
New BrunswickS4Yes
OntarioS5Yes
ManitobaS4Yes
Yukon TerritoryS4Yes
SaskatchewanS4Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentUnknownUnknownUnknown
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
9 - PollutionUnknownUnknownUnknown
9.3 - Agricultural & forestry effluentsUnknownUnknownUnknown
9.3.1 - Nutrient loadsUnknownUnknownUnknown
9.3.3 - Herbicides and pesticidesUnknownUnknownUnknown

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (2)
Montana (1)
AreaForestAcres
Marston Face # 172Kootenai National Forest9,098
Washington (1)
AreaForestAcres
Mt. BonaparteOkanogan National Forest10,891
References (7)
  1. Dodds, J. 2022. <i>Potamogeton zosteriformis</i> Rare Plant Profile. New Jersey Department of Environmental Protection, State Parks, Forests and Historic Sites, State Forest Fire Service and Forestry, Office of Natural Lands Management, New Jersey Natural Heritage Program, Trenton, NJ. 17 pp. [https://nj.gov/dep/parksandforests/natural/heritage/docs/potamogeton-zosteriformis-eel-grass-pondweed.pdf]
  2. 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.
  3. Global Biodiversity Information Facility (GBIF). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
  4. iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
  5. 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.
  6. Les, D. 2020. Aquatic Monocotyledons of North America: Ecology, Life History, and Systematics. CRC Press, Boca Raton, FL. 568 pp.
  7. Southwest Environmental Information Network (SEINet). 2024. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2024).