1. 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
   "The filmy fern clung to the bark of an old tree";
   - bristle fern
    
2. Any fern of the genus Hymenophyllum growing in tropical humid regions and having translucent leaves
   "The filmy fern's delicate fronds seemed to glow in the dim light of the rainforest";
   - film fern

Derived forms: filmy ferns

Type of: fern

Part of: genus Hymenophyllum, genus Trichomanes, Hymenophyllum, Trichomanes

Encyclopedia: Filmy fern