A perennial, submerged aquatic herb that is native to Eurasia. Tolerates fresh or slightly brackish water and can grow in shallow, deep, still or flowing water.
OverviewOther names for this plant include:
- Common names: curled pondweed, crisped pondweed
- It invades freshwater lakes, ponds, rivers, streams, and in slightly brackish waters. It can become dominant and invasive due to its tolerance for low light and low water temperatures.
- May outcompete other underwater plants and become dominant, which causes problems due to the formation of dense mats that interfere with recreational activities.
- It also causes an increase in phosphorus concentrations, causing an increase in algae blooms and a pile-up of dying P. crispus along the shore.
Classification in Wisconsin: Restricted
Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for curly-leaf pondweed was based upon this literature review developed by the department.
Leaves: All submersed and alternate with no leaf stalks; oblong, still, translucent leaves (4-10 cm long, 5-10 mm wide) have distinctly wavy edges with fine teeth and 3 main veins. Sheaths (stipules) up to 1 cm long are free of the leaf base and disintegrate with age.
Flowers: Tiny, with 4 petal-like lobes; in spikes 1-3 cm long on stalks up to 7 cm long.
Fruits & seeds: Seed-like achene (4-6mm long including 2-3 mm beak, back ridged).
Roots: Fibrous, from slender rhizomes.
Similar species: There are many native Potamogeton species native to Wisconsin.
See the reported locations of curly-leaf pondweed in Wisconsin.
Do you know of additional populations? Send us a report.
Mechanical: Due to the early growth period, management should happen in spring or early summer. Raking, cutting or harvesting reduces biomass and possibly reduces the production of turions.
Chemical: Diquat, endothall and fluridone can be effective.
View curly-leaf pondweed pictures in our photo gallery!
ResourcesSources for content:
- Washington State Department of Ecology: Potamogeton crispus
- Global Invasive Species Database: Potamogeton crispus
- Center for Invasive Species and Ecosystem Health, Invasive.org: Curly-leaf pondweed