filmy fern

(noun) any fern of the genus Trichomanes having large pinnatifid often translucent fronds; most are epiphytic on tree branches and twigs or terrestrial on mossy banks. Synonyms: bristle fern, filmy fern.

(noun) any fern of the genus Hymenophyllum growing in tropical humid regions and having translucent leaves. Synonyms: filmy fern, film fern.