Nuttalls waterweed

Elodea nuttallii


Photo credit: © Robert Videki
  • Elodea nuttallii is most common in calcareous waters and eutrophic waters because it has a high tissue demand for both phosphorus and nitrogen.

Similar Species: Elodea canadensis
Widely Spread Species:
  • Under Article 19 of Invasive Alien Species Regulation (1143/2014) Nuttall's waterweed has been identified as a Widely Spread Species in Northern Ireland and as such, management measures have been put in place to minimise its impacts.

  • Description:
  • E. nuttallii originated from North America. This species is very similar to another invasive specie know as E. canadensis (Canadian waterweed).
  • Both species grow in still or slow flowing eutrophic waters but E. nuttallii has replaced E. canadensis at many sites possibly due to increased eutrophication.
  • This is an aquatic weed that grows rapidly towards the surface of eutrophic freshwater systems without branching where they form a densely branched canopy.
  • E. nuttalli is perennial and over winters in Ireland as horizontal shoots which regenerate new lateral shoots as the temperature reaches 6-8°C.

Download N.I.E.A. ID guide

Origin and Distribution:
  • This species is native to North America but is now invasive in Britain where it is common.

  • E. nuttallii tends to dominate native macrophyte communities which may lead to there local extinction. Impacts have also been recorded on invertebrate communities.
  • This species may also have a significant impact on protected sites.
  • E. nuttallii is also known to replace other invasive species as the dominant species in an impacted ecosystem.
  • More recently data from Britain suggests that this species is now becoming replaced by Largarosiphon major.

How did it get here?
  • Traded as a garden plant.

Is it found in Northern Ireland?
  • This species now occurs in Northern Ireland. More distribution information can be found at NBN Atlas NI.

You can help by reporting any sightings: @ the Centre for Environmental Data & Recording (CEDaR) - Or via the iRecord App.
Prevent Spread:
  • Promote native species and biodiversity - use alternative, native plants
  • Know what you are buying/growing and source native Irish seed and plants
  • Do not swap plants and cuttings
  • Clean plants before adding to ponds (dispose of water away from water courses)
  • Follow control advice and watch out for hitchhikers - inspect new imported purchases for invasive pest and pathogens
  • Clean equipment before moving between waterbodies
  • Never collect plants from the wild
  • Safe disposal of plant material and growing media
  • Record all sightings.

Current Legislative Position (Listed on 03 August 2017) 
  • This species must not intentionally be brought into the Union; kept; bred; transported to, from or within the United Kingdom, unless for the transportation to facilities in the context of eradication; placed on the market; used or exchanged; permitted to reproduce, grown or cultivated; or released into the environment.
For further queries, you can contact the Invasive Non Native Species (INNS) Team in the Northern Ireland Environment Agency on 028 9056 9558 or Email:  

Species Related Files:

Invasive Species Ireland

Invasive Species Ireland