Report of a Pest Risk Analysis for Hydrocotyle ranunculoides

Hydrocotyle ranunculoides originates from the American continent and was introduced into the EPPO region as an ornamental plant for tropical aquaria and garden ponds, where it is still sold under its correct name, sometimes under other names (H. vulgaris, H. leucocephala, and H. natans which is a synonym of H. ranunculoides). The plant was first recorded as naturalised in the south-east of the UK in the 1980s (Newman, 2003). Naturalisation in the Netherlands and in Belgium was recorded in the last decade of the twentieth century (Baas & Duistermaat, 1999; Baas & Holverda, 1996; Krabben & Rotteveel, 2003; Verloove 2006, Invasive Species in Belgium Website). Deleterious impacts have been reported in these three countries. The species is also recorded in France, Ireland, Italy, Germany (see EPPO, 2009) but several EPPO countries are still free from H. ranunculoides and there are concerns that it may be able to enter and establish in further countries. This PRA assesses the risks of its further introduction into other EPPO countries and its current and predicted impact. An initial EPPO PRA was performed and approved in 2005. After the proposal of listing this species in the Directive 2000/29, the European Food Safety Authority reviewed the initial PRA and made some comments. The initial PRA is therefore revised in the view of the EFSA comments and of information having become available after the initial PRA (EFSA, 2007).