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Potamogeton gramineus

L.

Grassleaf Pondweed

G5Secure Found in 3 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.142488
Element CodePMPOT030D0
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
Grass-leaved Pondweed (EN) Potamot à feuilles de graminée (FR) Variableleaf Pondweed (EN) variableleaf 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 Date2024-09-27
Change Date1984-06-25
Edition Date2024-09-27
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 gramineus is a perennial aquatic forb occurring nearly worldwide in ponds, lakes, streams, and rivers. In North America, it occurs throughout Alaska and all of Canada, south to California, east to New Mexico, north to Colorado, east through Maryland, and north to Maine in the United States. There are over 4,000 occurrences of this taxon, which are potentially threatened by eutrophication, development, water diversion, alteration of hydrology, erosion, recreational activities, invasive species, climate change, 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 gramineus is considered secure.
Range Extent Comments
Potamogeton gramineus has a circumboreal global distribution (POWO 2024). In North America, it occurs throughout Alaska and all of Canada, south to California, east to New Mexico, north to Colorado, east through Maryland, and north to Maine in the United States (FNA 2000). Range extent was estimated to be over 76 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 4,000 occurrences rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024).
Threat Impact Comments
Potamogeton gramineus prefers poor nutrient conditions and has disappeared from some North American lakes that have became eutrophic as a consequence of agricultural and urban runoff (Les 2020). Additional threats are not widely documented but likely include development, water diversion, alteration of hydrology, erosion, recreational activities, invasive species, climate change, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species.
Ecology & Habitat

Diagnostic Characteristics

Stem terete or slightly flattened, not black spotted. Many submersed leaves more than 4 mm wide, 3-8 cm long, with 3-9 veins, sessile, not cordate or auriculate at the base. Stipular sheath 1-3 cm long. Beak of the achene less than 1.5 mm long and lacking a basal appendage. Plants not red tinged.

Habitat

Potamogeton gramineus occurs in a variety of aquatic habitat types, including "backwaters, bays (shallow), canals (irrigation), channels, coves (shallow), ditches (roadside), fens, flats (tidal), floodplains, lagoons, lakes (bog, kettle, oxbow), pannes (calcareous, interdunal), ponds (beaver, boggy, drying, glacial, kettle, sag, stock), pools (brook, meadow, muskeg, river, roadside), potholes, rivers, sloughs, streams (outlet), and tanks (cattle)" (Les 2020). It thrives in full sun, but it also tolerates low light levels. It occurs in water depths from 0.15 to 6 m, though it is more common in shallow waters. Most populations of this species are found in northern sites with clear water, low sediment nutrient levels, and a short growing season.

Ecology

This species is extremely variable in size and shape fluctuation, which may be due to differences in depth and velocity of the waters in which it grows.
Palustrine Habitats
FORESTED WETLANDBog/fen
Other Nations (2)
United StatesN5
ProvinceRankNative
DelawareSNRYes
CaliforniaSNRYes
WashingtonSNRYes
MichiganSNRYes
MinnesotaSNRYes
PennsylvaniaS1Yes
VermontS5Yes
OhioS1Yes
ArizonaSNRYes
West VirginiaSHYes
IdahoSNRYes
NebraskaSNRYes
New JerseySNRYes
North DakotaSNRYes
OregonSNRYes
MontanaS4Yes
IllinoisS2Yes
New YorkS5Yes
MassachusettsSNRYes
IowaS3Yes
South DakotaSNRYes
WyomingS3Yes
UtahSNRYes
ColoradoS3Yes
WisconsinSNRYes
New MexicoSNRYes
IndianaSNRYes
New HampshireSNRYes
AlaskaSNRYes
MaineSNRYes
Rhode IslandSNRYes
ConnecticutSNRYes
KansasSHYes
NevadaSNRYes
CanadaN5
ProvinceRankNative
New BrunswickS5Yes
Northwest TerritoriesS4Yes
ManitobaS5Yes
Nova ScotiaS5Yes
AlbertaS4Yes
LabradorS4Yes
QuebecS5Yes
SaskatchewanS4Yes
OntarioS5Yes
British ColumbiaS5Yes
NunavutS3Yes
Yukon TerritoryS4Yes
Island of NewfoundlandS5Yes
Threat Assessments
ThreatScopeSeverityTiming
9 - PollutionUnknownUnknownUnknown
9.1 - Domestic & urban waste waterUnknownUnknownUnknown
9.1.2 - Run-offUnknownUnknownUnknown

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (3)
Minnesota (1)
AreaForestAcres
Wood LakeSuperior National Forest596
Wyoming (2)
AreaForestAcres
Rock CreekMedicine Bow-Routt National Forest18,874
Snowy RangeMedicine Bow-Routt National Forest29,660
References (13)
  1. Britton, N. L. and A. Brown. 1913. An Illustrated Flora of the Northern United States and Canada. 3 vol. Dover Publications, Inc., N. Y. 2052 pp.
  2. Fassett, Norman C. 1940. A Manual of Aquatic Plants. McGraw- Hill Book Company, New York, New York. 382 p.
  3. Fernald, M.L. 1950 Gray's Manual of Botany, 8th ed. American Book Company, New York. 1632 pp.
  4. 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.
  5. Gleason, H.A., and A. Cronquist. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. New York Botanical Garden, Bronx, New York. 910 pp.
  6. Global Biodiversity Information Facility (GBIF). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
  7. iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
  8. 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.
  9. Les, D. 2020. Aquatic Monocotyledons of North America: Ecology, Life History, and Systematics. CRC Press, Boca Raton, FL. 568 pp.
  10. Linnaeus, C. 1753. Species Plantarum. First edition printed by Adlard & Son, Bartholomew Press, Dorking, Great Britain. 2 vol.
  11. Ogden, E. C. 1943. The broad-leaved species of <i>Potamogeton </i>of North America north of Mexico. Rhodora 45:57-105, 19-163, 171-214.
  12. Plants of the World Online (POWO). 2024. Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Online. Available: https://powo.science.kew.org/ (accessed 2024).
  13. Southwest Environmental Information Network (SEINet). 2024. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2024).