Japan Flora: Rhizomes creeping, branched, slender, 1-1.5 mm. across, sparsely scaly; fronds nearly glabrous to sparsely pubescent; stipes slender, 7-20(-25) cm. long, sparsely scaly, pale green, brownish toward base; scales membranous, pale brown, broadly lanceolate to linear-lanceolate, 2-5 mm. long, to 2 mm. wide, entire; blades broadly lanceolate, 10-20 cm. long, 2.5-6 cm. wide, gradually acute to acuminate, slightly to scarcely narrowed toward base, simply pinnate, the rachis often sparsely scaly; pinnae 10-15 pairs, herbaceous, oblong-ovate to elliptic, 1-3 cm. long, 5-8 mm. wide, obtuse to rounded, ses­sile, spreading, crenate, the upper ones adnate to the rachis, the lower ones undivided, lobed, cleft, or rarely parted; sori often diplazioid. Shaded places in lowlands and low mountains.

Hokkaido, Honshu, Shikoku, Kyushu. Korea, Ryukyus, Formosa, Philippines, and Malaysia. Common and variable, closely related to A, japonicum,

var. oldhamii (Hook. & Bak.) Ohwi. Plants smaller, with narrower fronds and fewer scales.

var. simplicifolium (Makino) Ohwi. Blades simply pinnate. Honshu (Izu Prov.), Shikoku, Kyushu; rare