Egeria heterostemon (Hydrocharitaceae), a new species from central Brazil, is described and illustrated. It is distinguished from congeneric species by its flowers having hetero morphic whorls of stamens, and by its long-stalked clavate staminodes, which are strongly papillose distally. Further, taxonomic notes: on Apalanthe granatensis (Humboldt & Bonpland) Planchon are presented, and a key to species of both genera is provided.1116366