Description from Flora of China
Based on Athyrium filix-femina (Linnaeus) Roth var. longipes Hara, Bot. Mag. (Tokyo) 48: 691. 1959; A. acutidentatum Ching; A. changbaishanense Ching & J. J. Chien; A. dailingense Ching; A. hebeiense Ching.
Rhizomes short, erect or ascending, apex densely clothed with dark brown, lanceolate, large scales. Fronds caespitose; fertile fronds 35-120 cm; stipe blackish brown at base, upward stramineous or pale purplish red, 15-55 cm, base 2.5-4(-6) mm in diam., similarly densely scaly, upward glabrate, with sparse brownish small scales; lamina 2-pinnate, ovate to ovate-lanceolate, 20-65 × 20-35 cm at middle, base rounded-truncate and hardly narrowed, apex acuminate; pinnae 15-18 pairs, basal 1 or 2 pairs of pinnae opposite, upper pinnae alternate, ascending, subsessile or shortly stalked (stalk ca. 2 mm), 1 or 2 pairs of pinnae not or slightly shortened, 10-20 cm; middle pinnae lanceolate to linear-lanceolate, 12-20 × 3-6 cm, base subequilateral, truncate or rounded-cuneate on basiscopic side, pinnate, apex long acuminate; pinnules 18-28 pairs, basal pinnules subopposite, broadly lanceolate; upper pinnules alternate, subspreading, subsessile, lanceolate to falcate-lanceolate, 1.5-3 cm × 5-9 mm at base, base subequilateral, slightly auriculate on acroscopic side, broadly cuneate on basiscopic side, decurrent and slightly adnate to costae, pinnatipartite to 1/2-2/3, apex acuminate or acute; pinnule segments 10-15 pairs, subtriangular, oblong, or lanceolate, oblique, toothed at apex and margin; veins inconspicuous adaxially, visible abaxially, pinnate in segments, lateral veins 2-4 pairs, oblique, simple. Lamina thickly herbaceous when dried, greenish brown, glabrate on both surfaces; rachis and costae brownish stramineous or pale purplish red, with sparse brownish, squarrose glandular hairs abaxially. Sori oblong, J-shaped, or horseshoe-shaped, inframedial on basal acroscopic veins, single per segment, often 2 or 3 pairs per basal large segments; indusia brownish, oblong, J-shaped, or horseshoe-shaped, membranous, erose at margin, persistent. Perispore surface without folds, with granular ornamentation. 2n = 80*.
Athyrium brevifrons is very close to A. rubripes, but their relationship is still in need of investigation.
The name "Athyrium brevifrons Naki" used for this taxon in FRPS (3(2): 162. 1999) was ascribed to Kitagawa (Rep. First Sci. Exped. Manchoukuo Sect. 4(2): 75. 1935), but that is a nomen nudum, as are most other citations given in FRPS. However, by including the valid taxon A. filix-femina (Linnaeus) Roth var. longipes as a synonym, Tagawa effectively validated the binomial Athyrium brevifrons Nakai ex Tagawa. The name A. multidentatum (Döll) Ching, based on Aspidium filix-femina Swartz var. multidentatum Döll, has been included within this taxon and would have priority, but Ching indicated that the inclusion was based on a misapplication of the name by Fomin (Fl. Sibir. Orient. Extremi 5: 108. 1930). Dölls protologue has not been seen, but if, as seems likely, it was based on European material Chings interpretation would seem correct. "Athyrium extensum" (Ching in Y. L. Zhang et al., Sporae Pterid. Sin. 209. 1976) belongs here but was not validly published because no Latin description or diagnosis, or reference to such, was provided (Melbourne Code, Art. 39.1).
Broad-leaved forests, mixed forests; 300-2100 m. Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, N Shandong, Shanxi [Japan, Korea, E Russia].