Floating Fern Family. Comprised of 2 genera and about 16 species of floating aquatic plants. Members of this family usually have relatively short stems that appear dichotomously branched, sometimes lacking roots with leaves that are either alternate and 2-lobed with 1 lobe green and floating and the other submerged and white or translucent or in whorls of 3 with 2 leaves unlobed and floating and the 3rd submerged.