Hydrocharis is a genus of aquatic plants in the family Hydrocharitaceae described as a genus by Carl Linnaeus in 1753. It is widespread across much of Europe and Asia, plus a few scattered locations in Africa. It is also reportedly naturalized in parts of North America. The best known species is Hydrocharis morsus-ranae, commonly called common or European frogbit, and occasionally water-poppy. The name "American frogbit" refers to another aquatic plant, Limnobium spongia. Three species are recognised: