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Plants evergreen. Rhizome ascending, 1.5-3 cm in diam. including stipe bases, upper part and basal stipes densely scaly; scales spreading, shiny, lanceolate or broadly lanceolate, ca. 7 × 1-1.5 mm, thickly membranous, entire. Fronds few, 25-65 cm; stipe pale greenish stramineous, 2.5-18 cm, 1-2 mm in diam. at base, sparsely covered with smaller scales above base; scales brown, lanceolate, membranous, margins fimbriate. Lamina 1-pinnate, narrowly elliptic-lanceolate, 15-45 × 2.5-6 cm at middle, gradually contracted below middle, 1-2.5 cm wide at base, acuminate or shortly acuminate; rachis pale greenish stramineous, without proliferous bulbils, abaxially sparsely scaly; scales brown, ovate-lanceolate, lower part peltate and appressed, membranous, margins fimbriate, apices caudate and long acuminate. Pinnae 20-50 pairs, alternate or nearly opposite, often obviously remote, upper pairs from middle of lamina upward attached at right angles to rachis, lower pairs ± reflexed, oblong or falcate, rarely falcate-lanceolate, middle pairs 1.5-3 cm × 4-7 mm, bases obviously asymmetrical, apices often obtuse-rounded, sometimes acute; acroscopic base with deltoid auricles, apex of auricles acute, proximal margins of auricles ± parallel to rachis, basiscopic margins of pinnae narrowly cuneate, attached at right angles or nearly right angles with rachis, acroscopic margins curved, distal margins often shallowly obtusely toothed, rarely acutely toothed; abaxially sparsely covered with short light brown microscales, adaxially subglabrous; frond texture papery; venation pinnate, often prominent abaxially, distinct adaxially; lateral veins robust, thickened and clavate apically, nearly reaching pinna margin, mostly dichotomous, rarely simple, pinnate on auricles; clavate and unusually swollen at ends (hydathodes). Sori small, in 1 row on each side of midrib, more numerous on acroscopic side, medial or close to margins, terminal on shorter veinlets, sometimes only apical pinnae fertile; indusia present, brown, shallowly erose or sparsely obtusely toothed, rarely lacerate.

● Rock crevices on limestone hills; 200-400 m. N Guangdong (Ruyuan), Guangxi, S Guizhou (Libo), S Hunan (Xinning).

Polystichum crassinervium is similar to P. gymnocarpium in habit, but it does not have slender and filiform microscales on the abaxial surface of pinnae; as well, the sori are indusiate.