European Frogbit

European frogbit (Hydrocharis morsus-ranae) is an annual free-floating macrophyte. This invasive species has long roots, up to 50cm, that are typically suspended in the water column rather than attached to the sediment beds. Most populations are considered dioecious, displaying small, white solitary female and clustered male flowers. The stem of European frogbit lacks a midline groove which distinguishes it from its native look-alike American frogbit (Limnobium spongia). European frogbit spreads rapidly and forms dense mats, which can limit light penetration and inhibit recreational use. You can learn more and report any sightings of this plant here. 

By Susan Nolde