Hippuris

a genus of aquatic perennial herbs of the family Hip- puridaceae. The flowers, which grow singly in the leaf axils, are small, plain, and apetalous. There is one stamen and one filamentous style. The genus includes three or four species, which occur in Europe, Asia, America, and Australia. Two or three species are found in the USSR. The most common one, H. vulgaris, grows in slowly flowing and stagnant waters, on muddy shores, and in certain types of swamps. The plant is eaten by deer and aquatic birds. H. Tetraphylla grows in the arctic zone—in the northeastern European USSR, in Eastern Siberia, and in the Far East.