Canadian Waterweed - Elodea canadensis

Forming deep green masses at or below the water surface, much branched, the shoots not collapsing out of water. Leaves in whorls, usually of three, the lowermost opposite, tongue shaped, at least 2 mm wide curved and minutely toothed. Flowers white or pale purple 4 to 5 mm, the male borne on long thread like stalks.

Elodea canadensis and Elodea nuttalli are very similar but can be separated by the leaf shape. E. canadensis has more oval leaves whilst E. nuttalli has strap-shaped leaves. Watch this video for a useful guide to both these species.

with a detailed image showing the leaf shape

A good image is required showing the leaf details.

Lakes, ponds and canals.

May to September.

Widespread and common in Britain.

Locally frequent in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 122 of the 617 tetrads.