Korea Flora: Habit: Evergreen perennial herb; leaves fasciculate from thick rhizome. Stipe: 20-40 cm long, densely scaly. Scales: Reddish-brown, linear-lanceolate; margins entire; larger ones up to 1 cm long; some bullate; becoming narrower and shorter upwards, readily deciduous.
Blade: Oblong-ovate to triangular-ovate, 25-50 cm × 15-30 cm; bipinnate. Pinnae: Lanceolate; long-acuminate. Pinnules: When shallowly divided: oblong; apex rounded or truncate-rounded; margins slightly serrulate, When deeply divided: apex obtuse or acute; base auriculate on both sides; shortly stalked; margins shallowly to halfway pinnatifid Sori: Arranged in 1-3 rows near costa or medial; indusium round-reniform with entire margins.

Habitat: Growing in evergreen forests of Jeju Island. 
Note: Distinguished by its habitat in Jeju's evergreen forests and dimorphic pinnules (shallowly to deeply divided). 

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

Japan Flora: Rhizomes short, ascending; fronds evergreen, stipes 20-40 cm. long, straw- colored or brownish, rather densely scaly; scales spreading, linear-lanceolate, 5-10(-15) mm. long, brown, gradually long- acuminate, entire; blades oblong- to deltoid-ovate, 25-50 cm. long, 15-30 cm. wide, bipinnate, the rachis rather densely scaly; pinnae 10-13 pairs, lanceolate to broadly so, 2-4 cm. wide, long-acuminate, the rachis with small brown ovate-saccate scales beneath; pinnules broadly lanceolate, elliptic to oblong, acute to obtuse or truncate at apex, sessile, entire or crenately mucronate-toothed, sometimes auricled on anterior side at base, nearly glabrous above, with hair like appressed scales beneath; sori mostly median, few, in 2 rows on the lower portion of the pinnules, 1-1.5 mm. across, entire, membranous on margin.          

Honshu (Kanto Distr. and westw.), Shikoku, Kyushu. Formosa and China.