Curlyleaf Pondweed (Potamogeton crispus)

Other Names: Curly Pondweed, Curly-leaf Pondweed, CLP

Plant Family: Pondweed, Potamogetonaceae

Wetland Indicator Status: OBL

Curlyleaf Pondweed (Potamogeton crispus), or CLP for short, is a highly invasive species of lakes, rivers, and deepwater wetlands.  This pondweed is a good invader largely because it fills a niche unexploited by native submerget plants.  It begins growing in fall, winter, or early spring and reaches the end of its growth cycle in mid-June when it dies back.  Few if any of our native aquatic plants begin to grow so early.  This allows CLP to form dense stands early in the year.  However, native vegetation will get some relief in competition with this species through the second half of the growing season.

Most aquatic vegetation surveys in lakes occur at the height of the growing season and may miss the early abundance of Curlyleaf Pondweed or miss the species entirely.   However, if someone visits a site early in the season and sees large CLP stands, they may be under the impression that it has replaced all the native vegetation.  To fully assess the effects of Curlyleaf Pondweed, observers must visit the site early and in mid-summer.

Curlyleaf Pondweed Potamogeton crispus
Herbarium preserved Curlyleaf Pondweed (Potamogeton crispus) and aquatic invasive species