Botanical atlas
Canadian Waterweed
Elodea canadensis
This plant is kept in the atlas for identification and safety, not for use. Read the safety notes below before handling it, and keep it away from children, cats, and food.
Canadian waterweed has never been a kitchen or medicine cabinet herb. Its real history belongs to ponds and aquariums, not apothecary shelves. When it was carried from North America to Britain in the 1830s, it spread through canals and waterways so quickly that Victorian naturalists nicknamed it a nuisance almost as fast as they admired it, and it soon became one of the most familiar plants in glass aquariums and garden ponds around the world. Generations of biology students have also met it under a microscope, watching its single-layered leaf cells stream with visible cytoplasm and bead tiny bubbles of oxygen when held to the light, a simple, quietly wonderful demonstration of photosynthesis at work.
Safety.
Canadian waterweed is not known to be toxic but has no history of food or medicinal use. It is also classified as invasive in many areas, so never release or plant it in natural waterways.
Our sister app HerbLens identifies canadian waterweed from a photo and keeps its full botanical portrait: growing guide, harvest notes, and look-alike warnings.
View on HerbLensHerbSense shares traditional herbal knowledge for education, not diagnosis or treatment. Herbs can interact with medicines and conditions. Speak with your doctor before acting on anything here, and seek care promptly for anything severe, sudden, or worsening.