Etymology Greek: drys, oak + pteron, a wing, which describes the shape of the pinnae, but the word pteris was used by the ancient Greeks for all ferns.

Description Rhizome: long-creeping, dark brown, forking.
Frond: 40 cm high by 15 cm wide, deciduous, monomorphic, blade/stipe ratio: 2:1 to 3:1.
Stipe: grooved, straw-colored, darker, purplish at the base, scaly at base, vascular bundles: 2, oblong at stipe base, becoming round above.
Blade: 2-pinnate pinnatifid, triangular to pentagonal, herbaceous, vivid green, only a few glands below.
Pinnae: 6 to 10 pair, the lowest pair, exactly opposite, attached at a swollen junction, each similar to the remainder of the blade, only slightly smaller; pinnules the lower, basal pinnule of the basal pinna, most divided; costae grooved above, continuous from rachis to costae; margins entire to crenate; veins free, simple or forked.
Sori: round, in rows near the margin, often merging at maturity, indusium: absent, sporangia: brownish, maturity: midsummer.
Dimensionality: blade displayed horizontally.

Culture Habitat: acidic woodland. Distribution: cicumboreal. Hardy to -40°C, USDA Zone 2, requires a cool summer.

Distinctive Characteristics horizontally held blade, a stand "a waving leaf blanket ... floating 10-20 cm above the ground," Øllgaard, Scandinavian Ferns.

Synonyms
Polypodium dryopteris L.
Dryopteris linnaeana C. Chr
Curranina dryopteris (L.) Wherry
Lastrea dryopteris (L.) Bory
Phegopteris dryopteris (L.) Fee
Thelypteris dryopteris (L.) Slosson
Aspidium dryopteris Baumg.
Carpogymnia dryopteris (L.) A. Löve & D. Löve
Cystopteris dryopteris (L.) A. & D. Löve
Filix pumila Gilib.
Nephrodium dryopteris (L.) Michx.
Polystichum dryopteris (L.) Roth