Features: Hill's Pondweed (Potamogeton hillii) grows in clear, cold ponds and slow- moving streams where the water is alkaline. It has an erect, branched form with thin elongated leaves which have fine bristles at their tips. Plants can become locally abundant and provide dense cover for amphibians and small fish. It flowers in summer and the small fruits are eaten by ducks. The seeds float.

Status: Special Concern Provincially and Nationally

Range: Hill's Pondweed grows in northeastern United States and Ontario, ranging from Michigan and Ontario south to Pennsylvania and east to Vermont. In Ontario, it is recorded from about 24 sites in the Bruce Peninsula, Manitoulin Island, Wellington County and Peel Regional Municipality. Range Maps

Threats: Hill's Pondweed was not discovered in Ontario until 1951 and so it is not clear whether, and by how much, historic declines have occurred. The main threats are water diversion, drainage and pollution.

Protection: There is no formal protection for the species in Ontario. Two sites are protected as part of the Bruce Peninsula National Park; three occur in Areas of Natural and Scientific Interest (ANSI), although this does not necessarily confer protection on them; and one occurs on Saugeen First Nations' territories. All others occur on private land.

Text Sources: COSEWIC 2005; Brownell 1986

Last Modified Date: June 2008