Identity
Unique IDELEMENT_GLOBAL.2.152133
Element CodePMPOT030G0
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 NamesIllinois pondweed (EN) Potamot d'Illinois (FR)
Concept ReferenceKartesz, 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 Date2025-08-19
Change Date1984-06-25
Edition Date2025-08-19
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 ReasonsPotamogeton illinoensis is a perennial aquatic forb occurring in alkaline waters of streams, rivers, lakes, ponds, and sloughs of North, Central, and South America and the West Indies. In North America, it occurs from Quebec west to the Northwest Territories and British Columbia, Canada, south to Florida, Texas, and California in the United States, and south to Mexico. There are over 400 estimated occurrences of this taxon rangewide, which are threatened by invasive species, eutrophication, recreational activities, and likely other threats in some places. Little is known about trends, but with a large range extent, high number of occurrences, abundant habitat, and broad habitat preferences, Potamogeton illinoensis is considered secure.
Range Extent CommentsPotamogeton illinoensis is a widespread species, occurring in North, Central, and South America and the West Indies (FNA 2000). In North America, it is found from Quebec west to the Northwest Territories and British Columbia, Canada, south to Florida, Texas, and California in the United States, and south to Mexico (FNA 2000, Weakley and the Southeastern Flora Team 2025). Range extent was estimated to be over 46 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 CommentsBy 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 more than 400 occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact CommentsAlthough threats are not widely documented, Potamogeton illinoensis is threatened by invasive species, eutrophication, recreational activities such as boating, and likely other threats in some places (Les 2020, NatureServe 2025). Invertebrate herbivory may also be a threat to this species, as it has been shown to reduce plant biomass by up to 63 percent (Les 2020).