Ontario Ferns website

Oak Fern
Gymnocarpium dryopteris

Oak Fern (Gymnocarpium dryopteris) Other common names: Northern Oak Fern

Other scientific names: Dryopteris disjuncta, Phegopteris dryopteris, Polypodium dryopteris, Thelypteris dryopteris

French names: Dryoptère disjointe

Family: Wood Fern Family (Dryopteridaceae)

Distinctive features: Single stalk. Three-part frond. Delicate aspect. Thrice divided. Woods.

Similar species:
  •   Bracken (Pteridium aquilinum) - much larger, more common, grows in open areas.

  •   Robert's Fern (Gymnocarpium robertianum) - very similar but rare in Ontario.

  •   Rattlesnake Fern (Botrypus virginianus) - more stout; fertile stalk extending upwards from center.


Fronds: Thrice divided

Height: 10-20 cm (4-8 in)

Sori: Underside of leaves.

Habitat: Forests;  Shaded forest.

Native/Non-native: Native

Status: Uncommon but not rare.

Photographs: 90 photographs available, of which 12 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Oak Fern (Gymnocarpium dryopteris)

A single frond of Oak Fern. Note the delicate aspect.

Oak Fern (Gymnocarpium dryopteris)

Oak Fern (Gymnocarpium dryopteris)

Oak Fern (Gymnocarpium dryopteris)

A young Oak Fern.

Oak Fern (Gymnocarpium dryopteris)

A "grove" of Oak Ferns.

Oak Fern (Gymnocarpium dryopteris)

The sori on the underside of the leaf.

Oak Fern (Gymnocarpium dryopteris)

Closer view of the sori.

Oak Fern (Gymnocarpium dryopteris)

Oak Fern (Gymnocarpium dryopteris)

The base of the stem.

Oak Fern (Gymnocarpium dryopteris)

A herbarium specimen, showing the entire plant. Again, note how delicate the stem is.

(Royal Botanical Gardens Herbarium,Burlington,Ontario).

Oak Fern (Gymnocarpium dryopteris)

Herbarium specimen showing the roots.

(Royal Botanical Gardens Herbarium,Burlington,Ontario).

Oak Fern (Gymnocarpium dryopteris)

A nice patch in the rain.