Stems long-creeping, 1--2(--3) mm diam. Leaves monomorphic, dying back in winter, often 1--2 cm apart, 15--60 cm. Petiole straw-colored, (8--)15--36 cm × 1--3 mm, at base with scales brownish, lanceolate, glabrous or sparingly hairy on margin. Blade narrowly to broadly deltate, usually somewhat longer than broad, (6--)12--25 cm, proximal pinnae longest and slightly narrowed at base, spreading or reflexed. Pinnae deeply pinnatifid, (3--)6--12 × 1--3.3 cm, lowermost 1--2 pairs separate, sessile, more distal pairs strongly adnate and connected by narrow rachis wing; segments entire, or those of proximal pinna pair sometimes crenate, uncommonly shallowly lobed; proximal pair of veins from adjacent segments meeting margin above sinus, veins simple or sometimes forked in lowermost pinnae. Indument abaxially of moderately to densely set hairs 0.3--1 mm along costae, veins, and blade tissue, costae also with scales light tan to shiny brown, ovate-lanceolate, spreading, to ca. 3 mm, scales sometimes sparingly hairy on margin. Sori subterminal on veins. n = 2 n = 90, apogamous. In moist, strongly to moderately acid soil, or on rocks in shaded rock crevices; 0--2200 m; Greenland; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon; Alaska, Conn., Del., Idaho, Ill., Ind., Iowa, Maine, Md., Mass., Mich., Minn., Mo., Mont., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., Tenn., Vt., Va., Wash., W.Va., Wis.; Eurasia.
Lvs scattered on long, slender, densely hairy and scaly rhizomes, to 5 dm, the pilose and scaly petiole mostly longer than the blade; blade 10-25 cm, mostly 1-2 times as long as wide, ciliate-margined, pinnate-pinnatifid, pinnae mostly 10-15 opposite or offset pairs below the pinnatifid apex, to 3 cm wide, approximate, broadly sessile and narrowly confluent along the rachis, only the lowest pair a little removed and often retrorsely divergent, commonly a little shorter than the second pair; segments of the pinnae oblong, obtuse, entire or the largest crenate to subpinnatifid; veins simple or once forked; rachis, costae and veins hairy beneath, the rachis also with abundant brown, lance-ovate scales; indusium none; 2n=90. Moist cliffs and woods; circumboreal, s. in Amer. to N.C., Tenn., Io., and Oreg. (Dryopteris p.; Phegopteris polypodioides)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.