Floating primrose - willow
Photo credit: @Père Igor
Ludwigia peploides - Floating primrose willow
Habitat: Inland surface waters
Description: The floating primrose-willow is a perennial aquatic plant native to the American continent.
Origin and Distribution: Native to North and South America. It was imported into France in the 19th century as an ornamental curiosity and has since become established in Belgium, France, Greece, Italy, the Netherlands and Spain.
Potential/known impacts: The plant is very fast-growing, being capable of doubling in extent in just three to four weeks. It not only shades out any other submerged plants but alters the chemistry of the aquatic environment, thereby reducing dissolved oxygen levels and disrupting entire freshwater ecosystems.
Additionally, it blocks up economically important waterways that are used for instance for recreation, fishing or navigation, causing major economic damage.
Given its prolific nature, there is a high risk that it will spread rapidly into further Member States.
How could it get here: Being sold as an ornamental pond plant.
From there, it has the potential to spread to waterways during flood events or through human-derived dumping.
Is it found in Ireland?: Not present in Ireland
Methods for prevention: Once established, the species is difficult to manage. EU-level action therefore includes a ban on sales and any planting or keeping, including in isolated ponds. Furthermore, the rapid eradication of any new populations is required to avoid the excessively high costs associated with its management later on. Where the species has become widely spread, appropriate management measures have to be taken.
Current Legislative Position (Listed on 03 August 2016)
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 Non Native Invasive Species Team in the Northern Ireland Environment Agency on 028 9056 9558.