Gymnocarpium is a small genus of ferns once placed with various other groups, including the dryopteroid ferns and the athyrioid ferns. Cladistic analysis has demonstrated that Gymnocarpium and Cystopteris

Cystopteris

Cystopteris is a genus of ferns. These are known generally as bladderferns or fragile ferns. They are found in temperate areas worldwide. This is a very diverse genus and within a species individuals can look quite different, especially in harsh environments where they experience stress and remain...

form a natural but relatively primitive clade that is basal to the asplenoid, 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, Eichenfarn
• Gymnocarpium fedtschenkoanum
• Gymnocarpium disjunctum
• Gymnocarpium jessoense -- western or Nahanni oak fern
• Gymnocarpium oyamense
• Gymnocarpium remotepinnatum
• Gymnocarpium robertianum
  Gymnocarpium robertianum
  Gymnocarpium robertianum is a fern of the family Woodsiaceae.-Description:Gymnocarpium robertianum has small , deltate, two to three pinnate fronds. Fronds arise from creeping rhizomes and have long, delicate rachis. The sori are borne in round clumps on the underside of the blade and lack an...
  
  -- limestone oak fern, Ruprechtsfarn

External links

• Gymnocarpium world species list