Etymology Marginalis means margined, referring to the position of the sori.

Description Rhizome: erect, soft, brown, chaffy scales.
Frond: 70 cm high by 20 cm wide, evergreen, monomorphic, blade/stipe ratio: 2:1 to 3:1.
Stipe: grooved, reddish brown at swollen base, becoming brownish green above, scaly at base; scales in dense tuft, pale tawny, vascular bundles: 7 in a c-shaped arc, sometimes fewer at the stipe apex.
Blade: 2-pinnate, ovate-lanceolate, leathery, deep green to felty blue-green, linear to ovate scales below, absent above.
Pinnae: 12 to 16 pair, in plane of blade, lanceolate; basal pinnae slightly reduced; pinnules basal pinnules longer than adjacent pinnules, basal basiscopic pinnule longer than basal acroscopic pinnule; costae grooved above, continuous from rachis to costae; margins shallowly crenate to nearly entire; veins free, forked.
Sori: round, in 1 row near the margin on the top two-thirds of the blade, indusium: reniform, silvery, attached at a sinus, sporangia: lead gray, then maturing to dark brown, maturity: midsummer.

Culture Habitat: rocky, wooded slopes and ravines, edges of woods, stream banks and roadbanks, and rock walls . Distribution: eastern North America, southern tip of Greenland. Hardy to -40°C, USDA Zone 2.

Distinctive Characteristics sori neatly arranged along the margins

Synonyms
Polypodium marginale L.
Aspidium filix-mas var. marginale Chr.
Filix-Mas marginalis Farwell
Lastrea marginalis Presl
Nephrodium marginale Michx.
Polystichum marginale Keys.
Thelypteris marginalis Nieuwl.