Canadian Waterweed
Category
Native Macrophyte
Common Name
Canadian Waterweed
Species Name
Elodea canadensis
Distribution / Status (Lake Tahoe)
Common native submerged macrophyte
Common native submerged macrophyte
Whorls of exactly three leaves, smooth texture, no tubers
Commonly Confused Species
Hyrilla (Hydrilla verticillata)
Growth Form
Submersed perennial
Leaf Shape
Linear to narrowly oblong
Leaf Arrangement
Mostly in whorls of three (occasionally four)
Leaf Size
6–15 mm long × 1–4 mm wide
Leaf Margin
Entire or faintly minutely serrulate
Leaf Apex & Base
Rounded to slightly acute apex; base tapered
Venation Pattern
Single prominent midrib
Stem Structure
Slender, sparingly branched, smooth; typically 20–100 cm long
Plant Height
1.2 m on average; up to 2.5 m maximum
Roots / Rhizomes
Slender, unbranched roots
Habitat Type
Clear, cool, oligotrophic lakes and slow streams (10–25 °C)
Depth Range
0.5–6 m
Substrate Preference
Sand, mud, or fine sediment
Light Preference
Requires moderate–high light; sensitive to turbidity
Ecological Role / Impact
Native macrophyte providing habitat and oxygenation
Flowering Period
July–September
Flower Description
Small white or faintly purple three-petaled flowers at surface (dioecious)
Reproductive Strategy
Primarily vegetative; also sexual reproduction via wind and water dispersal
Buoyancy / Adaptations
None specialized; flexible stems
Color
Bright green and translucent
Texture
Smooth and pliable; no indentation
Growth Rate / Seasonality
Moderate growth, peaking midsummer
References
Ausable River Association. (n.d.). Native and invasive plant lookalikes in the Ausable watershed. Ausable River Association. Retrieved from https://www.ausableriver.org/blog/native-and-invasive-plant-lookalikes-ausable-watershed
Knoke, D., & Giblin, D. (n.d.). Elodea canadensis. Burke Herbarium Image Collection, University of Washington.
Spicer, K. W., & Catling, P. M. (1988). The biology of Canadian weeds. 88. Elodea canadensis Michx. Canadian Journal of Plant Science, 68, 1035–1051.
U.S. Geological Survey. (n.d.). Elodea canadensis. Retrieved from https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=1142
Wells, R. D., de Winton, M. D., & Clayton, J. S. (1997). Successive macrophyte invasions within the submerged flora of Lake Tarawera, central North Island, New Zealand. New Zealand Journal of Marine and Freshwater Research, 31(4), 449–459.
Supporting Partners
The Martis Fund, a collaborative project of Martis Camp landowners, DMB/Highlands Group (the developers of Martis Camp), Mountain Area Preservation (MAP), and Sierra Watch. (See martisfund.org for more information)
The Community Impact Fund, Ashley Quinn Fund & the Foresight Fund held at the Tahoe Community Foundation
Additional thanks to the Tahoe Regional Planning Agency for providing specimens for studio filming
