Gymnocarpium
Gymnocarpium is a small genus of ferns, called oak ferns. It was once placed with various other groups, including the dryopteroid ferns and the athyrioid ferns. Cladistic analysis has demonstrated that Gymnocarpium and Cystopteris form a natural but relatively primitive clade that is basal to the asplenioid, thelypterioid, and athyrioid ferns comprehensively.
Gymnocarpium sori are small, round and naked. These ferns generally have a slender, creeping rhizome under the surface of the ground, and fairly thin-textured fronds.''Gymnocarpium'' species
- Gymnocarpium appalachianum – Appalachian oak fern
- Gymnocarpium brittonianum
- Gymnocarpium dryopteris – oak fern
- Gymnocarpium fedtschenkoanum
- Gymnocarpium disjunctum
- Gymnocarpium jessoense – western or Nahanni oak fern
- Gymnocarpium oyamense
- Gymnocarpium remotepinnatum
- Gymnocarpium robertianum – limestone oak fern
