EU LIFE project

Pistia stratiotes presents a high phytosanitary risk for the endangered area within the EPPO region with a low uncertainty. 

Further spread within and between countries is likely. 

The overall likelihood of P. stratiotes continuing to enter the EPPO region is high because the species is widely cultivated and continuously traded within the EPPO region. 

The risk of the species establishing in other EPPO countries is considered high as the plant is widely traded. 

However, the species is already banned from trade in Spain and Portugal. 

Potential spread as movement through irrigation and river systems may act to facilitate spread nationally and regionally. The potential high impact of the species within the EPPO region should be considered similar to that seen in other regions where the species has established and become invasive; i.e. Australia, Africa and the Southern States of the USA. Based on evidence elsewhere in the world, important ecosystem services are likely to be adversely affected by the presence of the plant. Impacts are likely to be more pronounced in countries and regions where the climate is most suited to establishment, growth and spread.