Rhizakenia

American frogbit

Limnobium laevigatum
Scientific classification
Kingdom:	Plantae
Clade:	Angiosperms
Clade:	Monocots
Order:	Alismatales
Family:	Hydrocharitaceae
Subfamily:	Hydrocharitoideae
Genus:	Limnobium Rich. 1814 not Schimp. 1853 (syn of Hygrohypnum in , a bryophyte)
Synonyms
Hydromystria G.Mey. Jalambicea (Cerv.) Cerv. Rhizakenia Raf. Trianea H.Karst. Hydrocharella Spruce ex Benth. & Hook.f.

Limnobium, common names spongeplant and American frogbit, is a group of aquatic plants in the Hydrocharitaceae described as a genus in 1814. It is widespread in freshwater environments in Latin America, the West Indies, and the United States.

Limnobium dubium (Blume) Shäffer-Fehre - Hydrocharis dubia (Blume) Backer