Hydrocharis morsusranae

Hydrocharis morsus-ranae L. is a species of the genus Hydrocharis known by the common name European frog-bit. It is a free-floating flowering plant that bears small white flowers. "Morsus-ranae" means "frog bite" in Latin, and it is part of this species' scientific name because frogs might seen as biting on the leaves. European frog-bit is often mistaken for an American frog-bit (Limnobium spongia) due to their similar looks and floating freely. It usually displays invasive behavior in Canada and North America, having a major impact on native ecosystems. However, European frog-bit is efficient in accumulating high concentrations of heavy metals and chemicals, removing waste from water....read more on Wikipedia.