zomes long-creeping, wiry, about 1 mm. across, scaly when young; fronds deciduous, slender, glabrous, often slightly glaucescent on the blades beneath; stipes slender, pale green, lustrous, sparsely scaly, 10-25 cm. long, dark brown at base; scales pale brown, thinly membranous, narrowly ovate, 2-3 mm. long, glabrous, those at base of stipes and on rhizomes broadly ovate, 3-4 mm. long; blades membranous, 5-angled, deltoid, 8-15 cm. long, slightly broader than long, glabrous, smooth; pinnae 3, the terminal as large as to only slightly larger than the lateral ones, deltoid, 5-10 cm. wide, gradually acute, bipinnadparted or in lower part bipinnate, the petioles 1.5-4 cm. long; pinnules deltoid-lanceolate, subacute to obtuse, sessile except for the lowest pair on the terminal pinna, sometimes petiolate, the ultimate pinnules narrowly oblong, obtuse, crenate to lobulate; sori in 2 series on the pinnules, nearer the margin than the costule. Coniferous woods.
Hokkaido, Honshu (centr. and n. distr.). Sakhalin, Korea, Himalayas, Siberia to Europe, and N. America.