Curly waterweed
Lagarosiphon major
Habitat
Still or slow-flowing nutrient rich water.
Key ID features
Dark green in colour with many branches.
Leaves grow in tight spirals around the stem.
Grows up to 3m in length.
Distribution
Widespread in England and Wales.
Impacts
Rapidly dominates a water body outcompeting native species, reducing biodiversity. Can also block intakes and reduces flood storage capacity.
Do’s & Don’ts
DON’T buy from any outlets for aquariums and water gardens. Often labelled ‘oxygenating plant’- it is against the law for it to be sold.
DO check whether this plant is present in your pond/aquarium - it’s really a monster in disguise!
DO dispose of invasive non-native plants responsibly – leave to dry in a sunny area 3m away from water. Can be composted or burned (in line with local restrictions) once completely dried.
DON’T break the law - Be Plant Wise - don’t dump invasive non-native plants in the wild or transfer to other ponds. If you cause curly waterweed to spread you may be guilty of an offence under the Invasive Alien Species (Enforcement & Permitting) Order 2019.
More Information
For more information visit the GB Non-Native Species Secretariat website.
Curly waterweed (GBNNSS)