Ogden's Pondweed (Potamogeton ogdenii) COSEWIC assessment and status report: chapter 6

Biology

Reproduction

Ogden’s pondweed can reproduce (uncommonly) by seeds and by the production of winter buds called turions (Hellquist & Hilton, 1983). Fruit is produced in mid-summer and the turions are produced towards the end of the growing season (Hellquist & Mertinooke-Jongkind, 2003). Ogden’s pondweed can also disperse and perennate by fragments (Hellquist & Hilton, 1983). In the US, Ogden’s pondweed reproduces primarily by turion production (Hellquist & Mertinooke-Jongkind, 2003).

Survival

Pondweeds are eaten by waterfowl and mammals; however, there are no known studies relating to Ogden’s pondweed in particular. Pondweeds could be eaten by aquatic insects and molluscs, but no specific information was found. No information was found on plant survival, age structure, or recruitment rate and none is reported for P. hillii, one of the parent species (Makkay, 2005).

Physiology

Ogden’s pondweed is associated with alkaline water (Crow & Hellquist, 2000; Hellquist & Hilton, 1983; Hellquist & Mertinooke-Jongkind, 2003). In the United States, alkalinity is reported as 71.5 to 107.0 mg/l CaCO3 (Hellquist & Mertinooke-Jongkind, 2003). No information was found regarding climatic or other tolerance limitations.

Movements/dispersal

The flowers of most species of pondweeds are wind pollinated, and the seeds are dispersed by water or waterfowl (Sculthorpe, 1967). Winter buds would also be dispersed by water and waterfowl (Haynes, 1974).  

Nutrition and interspecific interactions

Like other aquatic plants, narrow-leaved pondweeds provide habitat for aquatic invertebrates, food for mammals and waterfowl, and cover for amphibians and fish (Makkay, 2005). No information was found on the ecological role of Ogden’s pondweed in particular; however, it would probably serve a similar ecological role as other narrow-leaved pondweeds.

Behavior/adaptability

No information was found regarding the effects of stress, disturbance, or other environmental pressures on Ogden’s pondweed.

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