First report of Hydrocharis laevigata in Czechia
Hydrocharis laevigata (Hydrocharitaceae, synonym Limnobium laevigatum) is a floating aquatic plant native to South and Central America. It can invade freshwater habitats including shallow ponds, lakes, dams, reservoirs, and slow-moving rivers. It has the potential to outcompete native aquatic plant species and change the chemical composition of water bodies. The species has become invasive in Asia, Africa, Australia and North America, and is now spreading through European aquatic habitats. Naturalised populations have been found in Hungary and Spain (EPPO RS 2021/202), and the plant has been observed in Belgium, Germany, the Netherlands, Poland and Sweden. Recently it has been reported from France (RS 2026/022).
In 2024, two separate populations were discovered in natural aquatic habitats in Czechia for the first time. Occurrences of H. laevigata were recorded in the Central Bohemian region. The first population was found in a small stream near Český Brod and the second population in a former oxbow lake of the Elbe River near Kolín. The first population consisted of 30 plants. Both populations showed fragmentation of the stolons connecting the leaf rosettes and the plants reproduced vegetatively in their natural habitats. While the exact introduction pathway is unknown, it is likely to be the result of waste disposal by aquarists or gardeners.
Sources
Vávra M (2026) First record of non-native aquatic plant Hydrocharis laevigata (Humb. & Bonpl. ex Willd.) Byng & Christenh. in Czechia. BioInvasions Records 15(2), 271–279. https://doi.org/10.3391/bir.2026.15.2.05