Polystichum nipponicum Rosenstock, Repert. Spec. Nov. Regni Veg. 13: 190. 1914; Arachniodes anshunensis Ching & Y. T. Hsieh; A. gongshanensis Ching & Y. T. Hsieh; Byrsopteris nipponica (Rosenstock) Sa. Kurata; Polystichopsis nipponica (Rosenstock) Tagawa; Rumohra nipponica (Rosenstock) Ching.

Rhizome creeping, succulent at growing apex, 1-2.5 cm in diam., densely scaly; scales pale or reddish brown, ovate-lanceolate or lanceolate, to 7 × 1-2.5 mm, apically attenuate, thin and soft. Fronds remote or proximate, 0.7-1.5 m; stipe ochraceous or amber, 36-75 cm, 4-8 mm in diam., base scaly as rhizome, upward scales diminishing to glabrescent; lamina 3(or 4)-pinnate, lustrous yellowish green when dried, oblong-lanceolate or ovate-oblong, 40-75 × 25-45 cm, often thickly papery and flexible, base rounded-cuneate, apex acuminate or slightly attenuate, rachis glabrescent; pinnae 6-8(-10) pairs, alternate or lowest 1 or 2 pairs opposite, with to 2 cm stalk, obliquely spreading; lowest pinnae deltoid-lanceolate, 18-35 × ca. 10 cm, base rounded-cuneate, apex acuminate; primary pinnules 12-17 pairs, proximal ones with to 8 mm stalk, lanceolate, (basal basiscopic one 6-8 × 2-3 cm), base rounded-cuneate, apex acuminate, larger fronds with proximal 1-3 pairs of primary pinnules 2-pinnate; secondary pinnules shortly stalked or sessile, oblong, ca. 1.5 × 0.7 cm, base cuneate, apex acute, margin sharply dentate or pinnatifid, with mucronate teeth; upper pinnae gradually reduced; axes and veins of ultimate segments with brown, appressed, articulate hairs, and with a few minute brown ovate-based or linear scales abaxially. Sori terminal on veinlets, 2 or 3 pairs per ultimate segment, medial between midvein and margin; indusia pale brown, membranous, and entire.

Specimens from Guizhou and Yunnan are much larger in size than Japanese ones, and plants distributed in Yunnan occur at ca. 1000 meters higher in elevation.

Slopes by streams in broad-leaved forests or in shaded valleys, sometimes in coniferous forests or bamboos; 700-2300(-2800) m. Chongqing, Guangdong, Guizhou, Hunan, Jiangxi, Sichuan, Yunnan, Zhejiang [Japan].