Water Plantain

Species: Alisma plantago-aquatica

weed identification

common name
Water Plantain, Common Water-Plantain, Mad Dog Weed, European Water-Plantain

Long-stalked, to 80 cm, egg-shaped to oblong-elliptic leaves up to 28cm long and 10cm wide, with prominent network of veins. Base rounded to heart-shaped. Flowers are on a tall, rigid, leafless many-branched flowering stem with single, small long-stalked, 3-petalled flowers clustered in rings towards the ends of branches. Each flower lasts 1 day, flowers white in colour. Fruit like a mandarin.


Lakes, swamps, creeks, fringing on the edges of waterways.

native or exotic?

Seed or division of root stock. Flowering time: November – March


Seeds dispersed via wildlife and water movement


Fruit and leaves a food source for native wildlife.

What does Water Plantain look like?

Use these images below to help you decide whether you are dealing with Water Plantain.

Disadvantages of Water Plantain

Full coverage of a pond or dam by Water Plantain is uncommon but may cause issues such as:

  • Dense infestations may cause deoxygenation of the water
  • May shade out other aquatic plants
  • Dense infestations may cause fish and other aquatic life death
  • Can provide a breeding ground for mosquitos


AQ200 Aquatic Herbicide + Wetting Agent – Chemical Herbicide designed to kill emergent weeds quickly. Use on mild to severe infestations.

Aquatic Weed Rake and Razor Combo – DIY physical removal. Ideal for mild infestations, sensitive water bodies or to aid herbicide treatment.

Aquatic Harvesting – Large amphibious machine that cuts and clears emergent aquatic weeds. Book this service for severe infestations or for larger water bodies.

prevention options

Aerating Fountains – Reduces the severity and likelihood of aquatic weed infestations. Use in any body of water.