Latin: filix, fern + mas, male
Rhizome: erect, stout, branching, covered with old stipe bases.
Frond: 120 cm high by 25 cm wide, deciduous, monomorphic, erect to somewhat arching, blade/stipe ratio: 2:1 to 3:1.
Stipe: grooved, straw-brown, scales pale brown, vascular bundles: 5 or 7 in a c-shaped pattern.
Blade: pinnate-pinnatifid, almost 2-pinnate, rarely more, ovate-lanceolate, widest at the middle, herbaceous to somewhat leathery, mid green, scales thin out along the green rachis.
Pinnae: 16 to 24 pair, lanceolate, straight to slightly curved upwards; basal pinnae ovate-lanceolate, much reduced; pinnules basal pinnules ± same length as adjacent pinnules, basal lower pinnule and basal upper pinnule equal, fully attached to costa along the base; costae grooved above, continuous from rachis to costae; margins serrate; veins free, forked.
Sori: round, in 1 row between midrib and margin, on the upper half of the frond, indusium: reniform, pale green at first, then whitish, then leaden-gray, then rusty brown, then shriveling, at a sinus, sporangia: black or dark brown, maturity: late summer to mid autumn.
Habitat: the eastern North American variety appears only on calcareous soils, the European, Asian, and western North American variety most anywhere.
Distribution: North America, Europe, Asia.
Hardy to -30°C, USDA Zone 4.
Polypodium filix-mas L.
Lastrea filix-mas (L.) C. Presl.
Aspidium filix-mas (L.) Swartz
Filix-Mas filix-mas Farwell
Polystichum filix-mas (L.) Roth
Tectaria filix-mas Cav.
Thelypteris filix-mas Nieuwl.