Rhizomes long creeping; scales dark brown, subulate-lanceolate to lanceolate. Fronds monomorphic or slightly dimorphic (fertile laminae somewhat wider and more finely divided than sterile ones), closely to widely spaced. Stipe straw-colored above a sometimes brown base, 5-32 cm × ca. 1 mm. Lamina of sterile fronds narrowly lanceolate to lanceolate, 10-15 × 2.5-3.5 cm, 2-pinnate or 2-pinnate-pinnatifid. Lamina of fertile fronds larger than sterile lamina, lanceolate to ovate-lanceolate, 14-32 × 6-10 cm, apex long attenuate to somewhat caudate, 3-pinnate, papery when dry, green to grayish green, not farinose. Lateral pinnae 8-15 pairs, obliquely patent or curved upward, basal pair largest, lanceolate or ovate-lanceolate, 3-8 × 2-3 cm, stalked to 5-10 mm, apex long acuminate or caudate. Ultimate pinnules (segments) of sterile fronds obliquely ovate, apex sharply serrate. Ultimate pinnules (segments) of fertile fronds linear, 3-8 × ca. 1.5 mm, base narrowly winged and decurrent on costae, apex acuminate. Sori 2-7 mm. False indusia oblong to linear, entire. 2n = 87, 174.

As noted under Onychium japonicum, the O. japonicum/O. moupinense group is a polyploid complex that requires further study. Two varieties are tentatively accepted here, both in China.

Rock crevices under shrubs or in broad-leaved forests, shaded wet places; 500-1900 m. Hubei, Shaanxi, Sichuan, Yunnan [?Japan, Nepal].