Japan Flora: Rhizomes creeping; stipes usually as long as the blades, distinctly scaly especially toward the base, straw- colored, greenish; scales pale brown, membranous, broadly to narrowly lanceolate, 5-10 mm. long; blades nearly membranous, deltoid, 25-40 cm. long, nearly as wide, bipinnati- parted, thinly short-hairy on the costas of segments beneath, sometimes also on the rachis of pinnae beneath; pinnae 6-8 pairs, nearly opposite, narrowly oblong, 1G-25 cm. long, acuminate, the upper ones smaller, the lowest pinnae broader, ovate-oblong, with a much-reduced pinnule near base, sub- sessile or the petiolules 1-2 cm. long; pinnules oblong to broadly lanceolate, 1-2 cm. wide, acuminate to acute, very short-petiolulate or sessile, pinnatiparted, the ultimate pinnules oblong, 4-8 mm. long, 2-4 mm. wide, obtuse, toothed; sori rounded, 2-5 on each side of the pinnules, fnscous-brown, about 1 mm. across, naked.
Hokkaido, Honshu (centr. and n. distr.), Korea and Manchuria.