| marsh fern | (n) fern having pinnatifid fronds and growing in wet places; cosmopolitan in north temperate regions, Syn. Thelypteris palustris, Dryopteris thelypteris |
| oak fern | (n) bright blue-green fern widely distributed especially in damp acid woodlands of temperate northern hemisphere, Syn. Gymnocarpium dryopteris, Thelypteris dryopteris |
| snuffbox fern | (n) fern of northeastern North America, Syn. Dryopteris thelypteris pubescens, meadow fern, Thelypteris palustris pubescens |