Curly-leaf pondweed

Scientific Name: Potamogeton crispus

U.S. Geological Survey Great Lakes Science CenterCopyright Info

Identification: Curlyleaf pondweed is a rooted perennial plant that grows in shallow water. This species gets its name from its leaves’ wavy sides. The leaves are oblong in shape and dark green with a reddish hue. The small teeth along the edges of its leaves distinguish it from all other species of native Potamogeton in North America. The plant’s stems are flattened and branched, and its flowers are not conspicuous. The species is also known as curly pondweed, curly-leaved pondweed, and crispy-leaved pondweed.

Size: Stems grow up to 6 feet (2 m) in length. Leaves are 1-4 inches (2.5-10 cm) long.

Native Range: The plant is native to Eurasia, Africa, and Australia.

Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Potamogeton crispus are found here.

Full list of USGS occurrences

State/ProvinceYear of earliest observationYear of last observationTotal HUCs with observations†HUCs with observations†
Illinois191120111Little Calumet-Galien
Indiana191320083Little Calumet-Galien; St. Joseph; St. Joseph
Michigan1910201946Au Sable; Betsie-Platte; Black-Macatawa; Boardman-Charlevoix; Brevoort-Millecoquins; Brule; Cheboygan; Clinton; Escanaba; Flint; Great Lakes Region; Huron; Kalamazoo; Kawkawlin-Pine; Keweenaw Peninsula; Lake Erie; Lake Huron; Lake Michigan; Lake St. Clair; Little Calumet-Galien; Lower Grand; Manistee; Maple; Menominee; Muskegon; Northeastern Lake Michigan; Northwestern Lake Huron; Northwestern Lake Michigan; Ontonagon; Ottawa-Stony; Pere Marquette-White; Pigeon-Wiscoggin; Raisin; Saginaw; Shiawassee; Southeastern Lake Michigan; St. Clair; St. Clair-Detroit; St. Joseph; St. Marys; Tacoosh-Whitefish; Thornapple; Thunder Bay; Tiffin; Upper Grand; Western Lake Erie
Minnesota190620174Baptism-Brule; Cloquet; Lake Superior; St. Louis
New York1879201523Ausable River; Buffalo-Eighteenmile; Cattaraugus; Chateaugay-English; Chaumont-Perch; Chautauqua-Conneaut; Headwaters St. Lawrence River; Indian; Irondequoit-Ninemile; Lake Champlain; Lake Ontario; Lower Genesee; Mettawee River; Niagara; Northeastern Lake Ontario; Oak Orchard-Twelvemile; Oneida; Oswegatchie; Salmon-Sandy; Saranac River; Seneca; St. Lawrence; Upper Genesee
Ohio191020187Ashtabula-Chagrin; Black-Rocky; Cuyahoga; Huron-Vermilion; Lake Erie; Sandusky; St. Marys
Pennsylvania187920141Lake Erie
Vermont191120102Lake Champlain; Mettawee River
Wisconsin1955201822Bad-Montreal; Beartrap-Nemadji; Black-Presque Isle; Brule; Door-Kewaunee; Duck-Pensaukee; Fox; Lake Michigan; Lake Superior; Lake Winnebago; Lower Fox; Manitowoc-Sheboygan; Menominee; Milwaukee; Northwestern Lake Michigan; Oconto; Ontonagon; Peshtigo; Pike-Root; St. Louis; Upper Fox; Wolf

Table last updated 10/17/2019

† Populations may not be currently present.

* HUCs are not listed for areas where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).

Means of Introduction: This species was introduced into the U.S. in the mid-1800s and has since spread across much of the country. It has been planted intentionally for waterfowl and wildlife habitat. Curlyleaf pondweed may spread unintentionally as small plant fragments on boats and equipment that are not properly cleaned, by water used to transport fishes and fish eggs to hatcheries, or possibly by migrating waterfowl.

Status: Curlyleaf pondweed is established in most of the continental United States, excluding Maine and South Carolina. It is also present in the Canadian provinces of Alberta, British Columbia, Ontario, Quebec, and Saskatchewan. It was first sighted in the Lake Ontario drainage in 1879. By 1978, it was present across most of the Great Lakes basin.

Author: Illinois-Indiana Sea Grant

Contributing Agencies:
NOAA Sea Grant GLRI Logo

Revision Date: 8/30/2012

Citation for this information:
Illinois-Indiana Sea Grant, 2019, Curly-leaf pondweed: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI,, Revision Date: 8/30/2012, Access Date: 10/17/2019

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.