Korea Flora: Habit: Evergreen perennial herb; leaves fasciculate. Stipe: 20-30 cm long, densely scaly along with rachis. Scales: Reddish-brown to brown, membranous, entire; base with spine-like projections; linear-triangular to lanceolate-triangular; smaller ones ovate-triangular; apex long-acuminate. Blade: Ovate to oblong-ovate; apex acute; 30-60 cm × 20-30 cm; bipinnate; widest at base. Pinnae: Linear-lanceolate; shortly stalked; apex acute. Pinnules: Oblong-ovate; apex rounded or obtuse; base acute or rounded, broader on both sides; adaxial surface glabrous; abaxial costa with both bullate and flat scales. Sori: Submarginal, sometimes medial; indusium round-reniform with entire margins. Related Taxa: f. kinkiensis Kurata: Distinguished by dark brown scales on stipe and rachis

Habitat: Growing in Jeju Island.
Note: Characterized by spine-like projections at scale bases and mixture of bullate and flat scales on abaxial costa. 

[Translated from Flora of Korea by T.B. Lee]

Japan Flora: Rhizomes short; fronds evergreen; stipes 20-50 cm. long, densely scaly; scales spreading, membranous, brown, slightly lustrous, linear- to lanceolate-deltoid or sometimes ovate, 8-15 mm. long, narrowed to a filiform tip, prominently spine-toothed, except at the tip; blades oblong-ovate to ovate, 30-50 cm. long, 20-30 cm. wide, gradually or abruptly caudate- acuminate, broadest near base, bipinnate, the rachis densely scaly; pinnae 10-13 pairs, deltoid-lanceolate, 10-20 cm. long, 2.5-5 cm. wide, oblique, acuminate, usually broadest at base, short-petiolulate; pinnules thick-chartaceous, oblong-ovate to ovate, obtuse to rounded or subacute, broadly cuneate to rounded at base, usually with a small auricle on each side at base, sessile or very short-petiolulate, toothed, glabrous above, sometimes lobed, with short hairlike scales beneath while young; sori in 2 series, nearly median between the costule and margin; indusia orbicular-reniform, 1-1.2 mm. across, suben­tire. 

Honshu (s. Kanto through Tokaido and s. Shinano to Kinki Distr. and westw.), Shikoku, Kyushu. s. Korea and China.