State Status: THR
Federal Status: none
State Rank: S1
Global Rank: G5
Photo by USDA-NRCS
Counties with Mapped NHI Occurrences
Sheathed Pondweed (Stuckenia vaginata), a Wisconsin Threatened plant, is found in shallow water of lakes and creeks. Blooming occurs throughout July, fruiting early-August through early-September. The optimal identification period for this species is throughout August.
Potamogeton vaginatus
Sheathed pondweed is a submergent aquatic forb that has spikes with 5-12 nearly equidistant whorls of flowers, 3-8cm at maturity. Its fruits are 3-3.5mm. Its leaves are 1-2mm wide, stipular sheaths (at least of the primary leaves) are adnate, subinflated, 2-3 times as thick as the stem, 2-5cm, and open to the base.
The adnate stipule sheaths of this species make it unique from Potamogetons in Wisconsin. Stuckenia species also have adnate stipule sheaths and appear similar to Potamogetons, but can be distinguished by the percentage of the sheath that is adnate. In Stuckenia sp. the sheath is adnate for 80 to 90% of its length. In Potamogeton vaginatus, the sheath is adnate for closer to 50% of its length.
Blooming occurs throughout July, fruiting early-August through early-September.
Perennial. The optimal identification period for this species is throughout August.
Associated species include Potamogeton crispus, P richardsonii, P zosteriformis, Elodea canadensis, Hypericum boreale, Ranunculus longirostris, Vallisneria americana, Myriophyllum species, Ceratophyllum demersum, and Nymphaea odorata.
Sheathed pondweed is found in shallow water of lakes and creeks.
Avoid known individual plant locations and conduct operations elsewhere when they are least likely to cause damage. Ideally, this would involve frozen, snow-covered ground. However, in areas of the state where frozen conditions are unreliable, very dry soils late in the growing season might be the best available alternative. Consult with a biologist, if needed.
Avoid broadcast spraying of herbicides and use care with spot spraying.
Species of Greatest Conservation Need (SGCN) are associated with habitats (or natural communities) and places on the landscape. Understanding relationships among SGCN, natural communities and ecological landscapes help us make decisions about issues affecting SGCN and their habitat and how to respond. Download the Wildlife Action Plan association score spreadsheet to explore rare species, natural communities and ecological landscape associations
Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the Wisconsin Wildlife Action Plan because lack of information can threaten our ability to successfully preserve and care for natural resources.
