floating fern

(noun) pantropical aquatic fern. Synonyms: floating fern, Ceratopteris thalictroides.

(noun) aquatic fern of tropical America often used in aquariums. Synonyms: floating fern, water sprite, Ceratopteris pteridioides.

(noun) small free-floating aquatic fern from the eastern United States to tropical America; naturalized in western and southern Europe. Synonyms: mosquito fern, floating fern, Carolina pond fern, Azolla caroliniana.