PROTECTING WISCONSIN'S BIODIVERSITY

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Scientific Name	Common Name	Global Rank	State Rank	Federal Status	WI Status

Clasping-leaf Pondweed (Potamogeton perfoliatus)

State Status: SC

Federal Status: none

State Rank: S1

Global Rank: G5

Photo by USDA-NRCS

Counties with Mapped NHI Occurrences

Clasping-leaf Pondweed (Potamogeton perfoliatus), a Wisconsin Special Concern plant, is found in lakes and streams with sandy or rocky substrate. Blooming occurs July to October, fruiting mid-July to October. The optimal identification period for this species is July to October.

Identification

Clasping-leaf pondweed is a submergent aquatic forb up to 2.5m tall, with unbranched spikes that are cylindric and 1-7cm. Its fruits are greenish-brown, up to 3mm, with a short beak, shallow pits and three dorsal keels or ridges. Leaves are alternate, 1-7cm, round, often with a finely toothed tip and cordate bases that wrap entirely around stem (perfoliate), each has 7-15 veins with 3-5 prominent. Stipules are free and deciduous.

Distinguishing Characteristics and Similar Species

It can be distinguished from P richardsonii by its often perfoliate leaves (vs clasping), more slender stems and rounded or ovate leaves (vs lance-ovate and with a definite pointed tip).

Phenology and Reproduction

Phenology

Blooming occurs July to October, fruiting July to October.

Life Cycle, Optimum Time to Identify

Perennial. The optimal identification period for this species is July to October.

Habitat

Clasping-leaf pondweed prefers is found in lakes and streams with sandy or rocky substrate.

Avoidance Measures and Management Guidance

Avoidance Measures

Avoid broadcast spraying of herbicides and use care with spot spraying.

Management Guidance

This species is likely sensitive to water quality. Following BMPs around streams and buffering associated drainages will reduce eutrophication and prevent water quality degradation.

Wildlife Action Plan

Associated Natural Communities and Ecological Landscapes

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

Issues/Threats and Conservation Actions

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.

PROTECTING WISCONSIN'S BIODIVERSITY

Clasping-leaf Pondweed (Potamogeton perfoliatus)

Rare Species & Natural Communities

Additional Resources

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