Invasive Species - Curly-Leaf Pondweed (Potamogeton crispus)

Curly-leaf Pondweed is an aggressive invasive species. It begins to grow much earlier in the season than other weeds, leading to an uneven resource distribution that chokes out native species.

 

Curly-leaf Pondweed can be identified through a variety of physical characteristics. It appears reddish-brown in the water, but is actually green when examined out of water. Its leaves are wavy, stiff and crinkled, with a “crispy” texture (0.5 in. wide and 2-3 in. long). The leaves are arranged alternately around the stem and become more dense toward the end of the branches. The leaf tip is blunt and there are small teeth visible along the edge of the leaf (giving the leaf a serrated edge).

 

Curly-leaf Pondweed has slightly flattened stems and produces winter buds called turions (small, brown pine cones on shortened branches along stem). Flower stalks, when present, stick up above the water surface in June. Curly-leaf Pondweed begins growing in early spring before most pondweeds (leading to a major competitive advantage) and can form dense mats early on in the spring, but by mid summer, it tends to die off a bit.

 

Curly-leaf Pondweed prefers a habitat where it can grow in depths of up to 15 ft. It also tolerates low water clarity and will readily invade disturbed areas.

Runyan Lake Inc. currently treats curly-leaf pond weed with chemicals as part of our aquatic weed control program to control its growth.

Resources

Curly-Leaf Pondweed (IN DNR)

Curly-Leaf Pondweed Fact Sheet