Japan Flora: Stems erect, ascending to shortly decumbent at base, simple or sparsely forked, 7-25 cm. long, striate, bulbils in up­per part deep green, consisting of 3 oblong, obtuse, carnose, erect leaves about 5 mm. long; leaves rather thin and loose, spreading to subdeflexed, narrowly to broadly lanceolate, 6-20 mm. long, 1-5 mm. wide, acuminate to short-cuspidate, green, flat, sometimes unequal in size, costate on both sides especially so beneath, serrate and sometimes crisped on margin, nearly sessile; sporangia in axils of ordinary leaves, reniform, sessile.  Woods in mountains; Hokkaido, Honshu, Shikoku, Kyu­shu; rather common and variable. Sakhalin, s. Kuriles, Korea, Ryukyus, Formosa, China to India, and Malaysia.

var. longepetiolatum Spring. Leaves broader, distinctly narrowed to a petiolelike base. Honshu (s. distr.), Shikoku, Kyushu.

Russia Flora: Stems up to 25 cm tall. Stem at base ascending or shortly creeping, straight or curved, simple or slightly dichotomously branched, furrowed. Phyllodia (leaves) thin, brittle, spreading or slightly deflected, lanceolate, up to 20 mm long, 1-5 mm wide, pointed, green, flat, with clearly expressed veins, especially on the lower surface, with a serrated, sometimes reddish edge, narrowed toward the base. Sporangia located in the axils of ordinary phyllodia, narrow-kidney-shaped, 0.4 mm long. Reproductive buds few, located in upper part of stem, dark green, up to 5 mm long.

Northern Sakhalin, Amur region, Ussuri region, Southern Sakhalin, Southern Kuril Islands — Cedar-broadleaf, coniferous-broadleaf forests. VIII-IX. — General distribution: East Asia, Himalayas, Japan-China, Southeast Asia.