Mountain wood fern, eastern spreading wood fern, dryoptère arquée

Aspidium campylopterum Kunze, Amer. J. Sci. Arts, ser. 2, 6: 84. 1848; Dryopteris austriaca (Jacquin) Schinz & Thellung; D. spinulosa (Swartz) Watt var. americana (Fischer ex Kunze) Fernald; D. spinulosa var. concordiana (Davenport) Eastman

Leaves monomorphic, dying back in winter, 25--90 × 15--30 cm. Petiole 1/3 length of leaf, scaly at least at base; scales scattered, brown, sometimes with darker patch at base. Blade light green, deltate-ovate, 3-pinnate-pinnatifid, herbaceous, not glandular. Pinnae in plane of blade, lanceolate; basal pinnae deltate to broadly lanceolate, not reduced, basal pinnules equal to adjacent pinnules, basal basiscopic pinnule much longer and 2 times width of basal acroscopic pinnule (only in this species); pinnule margins toothed, teeth spine-tipped. Sori midway between midvein and margin of segments. Indusia usually lacking glands. 2 n = 164.

Cool, moist woods at increasing elevation southward; frequently only at summits of mountains; 0--1500 m; N.B., Nfld., N.S., P.E.I., Que.; Conn., Maine, Md., Mass., N.H., N.Y., N.C., R.I., Tenn., Vt., Va., W.Va.