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Curly-Leaf Pondweed

Curly-Leaf Pondweed

Curly-Leaf Pondweed

(Potamogeton crispus)

Priority: -  Control

Tags: Aquatic

Identification and Reproduction

Identification

  • Curly pondweed has wavy, toothed, alternate leaves.
  • The leaves become denser at the bottom of the stem.
  • The serrated leaves are a unique distinguishing feature of this species.
  • The leaves are green, reddish, or brown, and the plant has yellow or red rhizomes.
  • The plant grows up to five metres long, and forms dense mats of vegetation.


Reproduction

  • It has a winter annual type of life cycle.
  • It reproduces vegetatively with buds called “turions” which develop over winter.
  • It is one of the first aquatic plants to begin growing in spring, and it grows quickly during the season.
  • It also produces small flowers that can be found above water.
  • The flowers are in a terminal spike and have small fruits which it uses to reproduce sexually.

Habitat & Ecology

  • This plant can grow at cold temperatures and with little light.
  • It prefers brackish or alkaline water, and can easily thrive in polluted waters.
  • It survives over winters even under frozen water.
  • Curly pondweed is found in rivers, streams, marshes, and ponds.

Impacts

Ecological: 

  • The dense colonies produced by Curly pondweed can block aquatic activity and obstruct fish movements.
  • The vegetation can create eutrophication (increased phosphorus concentrations in waterways), which cause blooms of algae.
  • The plant outcompetes native aquatic vegetation and reduce biodiversity.

Management

  • Prevent transport of Curly pondweed by cleaning, draining, and drying boats and other aquatic equipment after leaving bodies of water.
  • Do not purchase Curly pondweed as aquarium vegetation. Never dispose of aquarium plants into drains or waterways.

Mechanical/Manual Control:

  • Mechanical removal can be done by raking out the plant early in the season, but this will not remove all parts of the plant.
  • Any plant parts removed should be disposed of in a landfill.
  • Benthic barriers can also be used to restrict light and growth. 

Resources

For more identification and control methods for curly-leaf pondweed check out the Invasive Species Council of Manitoba's page here

Header photo (Leslie J. Mehroff).