| gymnocarpium | (n) oak ferns: in some classification systems included in genus Thelypteris, Syn. genus Gymnocarpium |
| limestone fern | (n) yellow-green fern of rocky areas of northern hemisphere, Syn. northern oak fern, Gymnocarpium robertianum |
| oak fern | (n) bright blue-green fern widely distributed especially in damp acid woodlands of temperate northern hemisphere, Syn. Gymnocarpium dryopteris, Thelypteris dryopteris |