Fronds 1 or 2--4 coherent in small groups, wide tongue-shaped or ovate, 3--9 mm, 1.5--4 times as long as wide, rounded at tip; tract of elongated cells running between median line and edge of lower wall of pouch; area of air spaces within frond rarely longer than wide; angle of pouch 70°--120°°; flowering fronds narrower than most vegetative ones. Fruits 0.41--0.44 mm. 2n = 40, 42. Flowering (very rare) throughout year. Mesotrophic, quiet waters in subtropical to tropical regions with mild winters; 0--200 m; Calif., Fla., La., Tex.; Mexico; West Indies; Central America; South America.