Description from Flora of China
Rhizome robust, erect, ca. 10 cm tall, with dense fleshy thick roots, apex densely scaly; scales yellow-brown, linear-lanceolate, ca. 12 × 1 mm, membranous, margin black, thin, toothed; fronds caespitose. Fertile frond more than 1 m; stipe brown at base, upward green-stramineous, robust, ca. 50 cm, ca. 7 mm in diam., base densely scaly like rhizome, upward gradually glabrous, shallowly grooved adaxially; rachis green-stramineous or pale brown-stramineous, with sparse brown or dark brown linear scales, shallowly broadly grooved on adaxial side; lamina 1-imparipinnate, elliptic, more than 80 × 30 cm; lateral pinnae 12 pairs, subequal in size, lower pinnae opposite or subopposite, upper pinnae alternate, oblique, with stalk ca. 5 mm, elliptic-lanceolate, ca. 22 × 5.5 cm, base cuneate, margin entire or repand, margin in distal part of pinna occasionally shallowly crenate, incurved when dry, apex long acuminate, usually subfalcate; base of apical pinna asymmetrical, oblique, occasionally 1 or 2 auriculate or nearly free pinnatilobate; costae prominent, rounded on abaxial side, shallowly grooved on adaxial side, sparsely scaly with scales red-brown linear abaxially; veinlets prominent on both surfaces, oblique, 4 or 5 per veinlet group, thin, reaching margin of lamina. Lamina papery, grass-green or brown-green when dry. Sori and indusia long linear, sori on acroscopic veinlets longest, double, from midrib to near margin of pinna, 1-3 per veinlet group. Spores reniform, perispore hyaline, with some rugate, inconspicuous, granular projections.
The fertile fronds of young plants of Diplazium splendens have only 3-5 pinnae.
Evergreen broad-leaved forests in valleys, beside streamlets; 100-500 m. N Guangdong, Guangxi, S Hunan, SE Yunnan [Vietnam].