Nuttalls waterweed
Elodea nuttallii
Overview
Photo credit: © Robert Videki
Habitat:
Similar Species: Elodea canadensis
Widely Spread Species:
Origin and Distribution:
Impacts:
How did it get here?
Is it found in Ireland or Northern Ireland?
You can help by reporting any sightings:
Current Legislative Position (Listed on 03 August 2017)
Habitat:
- 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.
Impacts:
- 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 Ireland or Northern Ireland?
- This species now occurs in both Ireland and Northern Ireland.
- More information can be found at NBDC and NBN Atlas NI.
You can help by reporting any sightings:
- If it is in Northern Ireland @ the Centre for Environmental Data & Recording (CEDaR) - Or via the iRecord App.
- If your sighting is in Ireland please report @ the National Biodiversity Data Centre (NBDC).

Static Distribution Map as of December 2019 - Courtesy of CEDaR
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.