Curly-leaf Pondweed

Potamogeton crispus

Photo: Dennis Roberge, Maine Volunteer Lake Monitoring Program. Drawing: University of Florida/IFAS Center for Aquatic and Invasive Plants.


Curly-leaf pondweed is a submerged plant with strap-shaped leaves, similar to many of Maine 's native pondweeds. However, unlike our native pondweeds, Curly-leaf pondweed leaves are distinctly ruffled with finely serrated edges. It grows in large dense beds.

General Information

Curly-leaf pondweed, a native plant of Europe and Asia, is a threat to lakes and ponds throughout the United States. This species was confirmed in a small pond in southwestern Maine in 2004. It is also present in nearby Massachusetts, New Hampshire, Vermont, Connecticut, New York, and Rhode Island.

Curly-leaf pondweed is adapted to growing in cool conditions. Plants sprout from rhizomes and turions (a hard vegetative bud) in the fall and grow through the winter, reaching maturity early in the season (late spring through early summer). Plants generally die back by mid-July after releasing seeds and more importantly the turions. Once released, the turions scatter, floating through the water and sinking to the bottom where they lie dormant until the water begins to cool again in the fall.