a graceful light green polypody fern, Thelypteris dryopteris, having a creeping rhizome, found in acid woodlands and on rocks in the northern hemisphere
oak fern in American English
noun
a small woodland fern, Gymnocarpium dryopteris, of northern regions, having triangular, pinnate fronds that slant horizontally
Word origin
[1540–50; trans. of L dryopteris ‹ Gk dryopterís, equiv. to dryo- (comb. form of drŷs oak) + ptéris fern]
Examples of 'oak fern' in a sentence
oak fern
Other noteworthy plants which occur are toothwort, oak fern, bird's-nest orchid and broad-leaved helleborine.
Perring, Franklyn A Guide to Britain's Conservation Heritage (1991)