Scientific Name: Potamogeton ogdenii
Taxonomy Group: Vascular Plants
Last COSEWIC Assessment: April 2007
Last COSEWIC Designation: Endangered
SARA Status: Schedule 1, Endangered
Image of Ogden's Pondweed
Ogden’s Pondweed was first described in 1983 based on specimens gathered in 1970. This is a new species, Potamogeton ogdenii, which likely developed from a cross between P. hillii and P. zosteriformis.
Ogden’s Pondweed is a submerged aquatic plant. The filiform stem is stiff and profusely branched. The greenish brown leaves are long and narrow, measuring 5 to 7 cm in length. Very occasionally, the plant produces dark green fruits that occur in cylindrical spikes measuring 5 to 11 mm in length. In the absence of flowers and fruit, it is difficult to distinguish this annual from other narrow-leaved species of the Potamogeton genus.
Distribution and Population
Ogden’s Pondweed occurs in southern Ontario, western Connecticut, central New York State, central Vermont, and western Massachusetts. There are 19 populations globally, eight of which are considered historic. In Canada, this species has only been observed in three sites in southeast Ontario, where it was last collected in 1987. Canadian Ogden’s Pondweed populations have been noted in Hastings County (1873), in Murphy’s Point Provincial Park (1974), and at the Davis Lock on the Rideau Canal (1987). Since these sites could not be confirmed in 2005 and 2006, the species' current abundance is not known. However, the existence of suitable environments in the vicinity of the two most recently documented sites suggests that the species probably still occurs in Canada. Given the overall scarcity of Ogden’s Pondweed in adjacent states, it is unlikely that American populations could help replenish Ontario populations.
Ogden’s Pondweed grows in clear, slow-moving streams, beaver ponds, and lakes. Both Ontario sites are associated with marble bedrock, which means that the water in these aquatic habitats is hard or alkaline. Since very few sites have been documented in Ontario, little is known about this species’ general habitat trends. However, the unmistakable disappearance of beaver pond habitats in the Murphy’s Point site in recent years has resulted in a reduction of the available habitat. In addition, the presence of invasive aquatic plants in the vicinity of presumed populations suggests a degradation of the quality of this species’ habitat.
Although Ogden’s Pondweed rarely reproduces, the process generally involves the production of winter buds (named hibernacula) or, even more rarely, the production of seeds. Winter buds and seeds are dispersed by water or aquatic birds. Like other aquatic plants, Ogden’s Pondweed is likely a component of the habitats of aquatic invertebrates, as well as food for mammals and aquatic birds, and shelter for amphibians and fish. Very little is known about this recently discovered species.
Potential threats to Canadian populations of Ogden’s Pondweed include the destruction of its habitat (such as the disappearance of beaver ponds) and competition from invasive aquatic plants like the Eurasian water-milfoil.
Federal ProtectionThe Ogden's Pondweed is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Since Ogden’s Pondweed occurs in the Rideau Canal area, which is a national historic site, it is protected under the Canada National Parks Act. Its habitat in the Murphy’s Point site, an Ontario provincial park, is also protected.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for Ogden’s Pondweed (Potamogeton ogdenii) in Canada
Status Final posting on SAR registry
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
9 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2007 (2007)2007 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
Recovery Document Posting Plans
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