any of a genus (Elodea) of submerged water plants of the frog's-bit family, with whorls of short, grasslike leaves: often used in aquariums because it releases large amounts of oxygen
See elodea in American Heritage Dictionary 4
(ĭ-lōˈdē-ə)
noun
Any of various small, submersed herbs of the genus Elodea, having grasslike leaves.