Broad-leaf Pondweeds (Potamogeton spp.)

Large-leaf pondweed illustration
Claspingleaf pondweed illustration
Floating-leaf pondweed illustration

Common names: Large-leaf pondweed, claspingleaf (Richardson) pondweed, floating-leaf pondweed, whitestem pondweed, broad-leaf cabbage, musky cabbage, bass weed.

Location: Found in lakes and streams, growing in depths up to 20 feet; often grow near drop-offs.

Description: Leaves 2 to 8 inches long; large-leaf and claspingleaf pondweeds grow below the water surface, except for the flowering stalk; floating-leaf pondweed grows below the water surface, except for their flowering stalk and large, floating leaves; all species have thin and delicate submerged leaves, tough stems that are firmly rooted, and a stiff appearance when out of the water.

Hints to identify: Leaves alternate along the stem. Often grow in patches or beds; have small seed heads crowded into spikes, often sticking up above water from June through August. Floating-leaf pondweed----Floating leaves are slightly heart-shaped. Large-leaf pondweed----Floating leaves are oval-shaped; submerged leaves are large and wavy; plants are seldom branched. Claspingleaf pondweed----Leaves are wide and wavy with a broad base that clasps the stem; plant often branches toward tip; often confused with curlyleaf pondweed, which has small "teeth" along leaf edges (see page 31), but claspingleaf pondweed has no "teeth" on leaf edges.

Importance of plants: Broad-leaf pondweeds provide excellent habitat for panfish, largemouth bass, muskellunge, and northern pike; bluegills nest near these plants and eat insects and other small animals found on the leaves; walleyes use these pondweeds for cover.

Management strategy: See DNR regulations. These plants are important fish habitat, so it is best to let them be. Removing them may allow less-desirable aquatic plants to move in. These plants are also highly resistant to chemical control. For small problem areas, try raking or cutting the plants.