floating fern
n 1: pantropical aquatic fern [syn: {floating fern},
{Ceratopteris thalictroides}]
2: aquatic fern of tropical America often used in aquariums
[syn: {floating fern}, {water sprite}, {Ceratopteris
pteridioides}]
3: small free-floating aquatic fern from the eastern United
States to tropical America; naturalized in western and
southern Europe [syn: {mosquito fern}, {floating fern},
{Carolina pond fern}, {Azolla caroliniana}]