Canada Waterweed (Elodea canadensis)
Common names: Elodea (pronounced el-oh-DEE-a), American elodea, common elodea, anacharis, Canada waterweed.
Location: Found in lakes in depths up to 10 feet, often in hard water, and near stream inlets.
Description: Grows entirely underwater, except for a small white flower that blooms during the summer; has branched stems; plants and leaves are usually a dark, grass-green color; leaves are oval-shaped and arranged in clusters of three or four around the stem.
Hints to identify: Look for leaf clusters compacted near the tip and spaced farther apart down the stem; stems are brittle, branched, and form a large mass near the lake bottom; white flowers have three to four petals and bloom during the summer; flowers are attached to the stem by a threadlike stalk.
Importance of plant: Provides habitat for many small aquatic animals, which fish and wildlife eat; excellent oxygen producer; attractive leaves make it a popular aquarium plant. However, dense growth of this plant can create a nuisance, and its closed, compact structure is not ideal fish habitat.
Management strategy: See DNR regulations. Canada waterweed is often associated with nuisance conditions. If the plant is controlled by cutting or pulling, pick up all fragments--they can grow into new plants. Aquatic herbicides can be an effective control method.