Elodea is an invasive, perennial aquatic plant or submergent macrophyte, native to most of North America.
Young plants initially start with a seedling stem with roots growing in mud at the bottom of the water; further adventitious roots are produced at intervals along the stem, which may hang free in the water or anchor into the bottom. It grows indefinitely at the stem tips and single specimens may reach lengths of 3 m or more.
The leaves are bright green, translucent, oblong, 6-17 mm long and 1-4 mm broad, that develop in whorls of three (rarely two or four) round the stem. It lives entirely underwater with the exception of the small white or pale purple flowers which float at the surface and are attached to the plant by delicate stalks. It requires summer water temperatures of 10-25 °C and moderate to brigelodiaht lighting.
Elodea was first identified in Lakelse Lake in 1999 and was actually the impetus of the Lakelse Watershed Stewards Society who was concerned about the apparent infiltration of this weed. It grows rapidly in favorable conditions and can choke shallow ponds, lakes, and the margins of some slow-flowing rivers. It spreads rapidly by fragmentation, which can be generated by motor boats and other similar activities. It was first noticed in significant amounts near the Furlong Bay Campground and by 2004 was found in all parts of the lake. It seems to be a cyclic plant with natural rhythms of population blooms and decline. As a concern in 2004 and 2005, it seems to be in decline at the moment. Plans have been made to map out and survey the current elodea situation.
Other Information About Elodea
In a study of Wabamun Lake in Alberta, consultants postulated that new colonies of Elodea were initiated in areas where sediment is abundant in iron, where it thrives in nuisance proportions, lasting from 1 year to 9 years depending on iron reserves and replenishment. (The Biology of Canadian Weeds, 1988)