Expert working group 06-2010, core member consultation 06-2011. This PRA supported the addition of the plant to the EPPO A2 List.

Although regulated in some countries, the probability of entry by intentional import as an ornamental aquatic plant for use outdoors is very likely, as the species already entered the EPPO region, and continues to enter. Uncertainty is low. 

L. grandiflora has already established in at least 8 countries of the EPPO region, the probability of establishment is therefore very high, the uncertainty is low. According to the climatic prediction, additional countries are at risk. In addition, the overall probability of spread is high, uncertainty is medium. 

Economic impacts: major impacts considering the management cost, low uncertainty. Any economic benefit of the introduction of this plant as an ornamental aquatic plant is heavily outweighed by management costs. 

Environmental impacts: major, low uncertainty. Invasion of slow flowing waters, loss of biodiversity degradation and modification of aquatic ecosystem including protected habitats. 

Social impact: moderate, with low uncertainty. Where it occurs, it has an impact on recreational activities, it can also create favorable conditions for mosquito development, increased risk of flooding. 

The part of the EPPO region which seem the most economically at risk are the Atlantic and Mediterranean areas, as well as the Black sea area