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.