Japan Flora: Rhizomes stout, short, erect or ascending, densely covered with the stubs of old stipes; fronds crowded; stipes of sterile fronds 7-15 cm. long, compressed-trigonous at base; sterile blades 30-60 cm. long, 10-20 cm. wide, abruptly acuminate, slightly narrowed at base, the rachis slightly raised, with flat faces on both sides; pinnae horizontally spreading, linear-lanceolate or broadly linear, the median ones 5-10 cm. long, 8-15 mm. wide, widely decurrent, acutely incurved-toothed in lower por­tion, irregularly and more coarsely so toward the long-acumi­nate tip; fertile pinnae linear, 3-8 cm. long, obtuse, widely de­current. Woods in mountains.

Hokkaido, Honshu, Shi­koku, Kyushu; rare southw. s. Kuriles.