Korea Flora: Rhizome: Small, erect, bearing 3-10 densely arranged leaves. Stipe: 1-10 cm long; brownish at base; young stipes with glandular hair-like scales. Frond: Blade bipinnate, elongated-ovate to elongated-ovate or elongated-elliptical; 2-15 cm × 1-4 cm; apex obtuse to slightly acute. Pinnae: 3-8 pairs; short-stalked. Pinnules: Deeply pinnatifid or serrate; obovate-cuneate; similar color on both surfaces; single vein per tooth or segment. Sori: 1-3 per segment. Indusium: Linear to elongated-elliptical; yellowish-white; 1-3 mm long. Habitat: On moist rocks in forests; Jangsangot, Jeju Island, and Geomundo Island. Evergreen perennial, though leaves wither during winter in northern regions. Note: Known as named for its smaller size compared to A. incisum, with distinctive green petioles.
Japan Flora: Rhizomes short, the scales membranous, deltoid-lanceolate, 1 mm. long, long-acuminate, entire, dark brown; stipes pale green, subcapillary to very slender, 1-10 cm. long, brownish at base, with minute hairlike scales while young; blades membranous, oblong-ovate to narrowly oblong, 2-10(-15) cm. long, 1-3 (-4) cm. wide, bipinnate, the smaller ones bipinnatiparted, obtuse to acuminate; pinnae 3-8 pairs, obliquely spreading, ovate to rhombic-ovate, the smaller ones rhombic-orbicular, usually short-petiolulate, pinnate to subternate, the ultimate ternate, 4-20(-30) mm. long, obtuse; pinnules membranous, few, obovate or rhombic-ovate, 3-5 mm. long, 3-4 mm. wide, with coarse 1-veined teeth or lobes; sori ascending, few on a pinnule; indusia thinly membranous, oblong to linear, 1-3 mm. long, white.
Hokkaido (Kamuikotan, fide Miyabe & Kudo), Honshu, Shikoku, Kyushu. China to India