Description from Flora of China
Polystichum nigrospinosum Ching, Bull. Fan Mem. Inst. Biol. 2: 191. 1931; Rumohra nigrospinosa (Ching) Ching.
Rhizome shortly creeping, stiff, apex densely scaly; scales coal-black, broadly lanceolate or lanceolate, to 12 × 1-2.5 mm, firm, thick, apex attenuate and hairlike. Fronds approximate, 0.8-1.2 m; stipe dull amber, 45-65 cm, 3-6(-8) mm in diam., base densely scaly as rhizome, upward with similar but smaller blackened scales; lamina 4-pinnate, dark green when dried, oblong-ovate, 35-55 × 28-32 cm, thinly herbaceous, base cuneate or rounded, apex acuminate, rachis scaly as distal portion of stipe; pinnae ca. 15 pairs, stalked, alternate, obliquely spreading, contiguous; lowest pinnae deltoid-lanceolate, to 25 × 15 cm, base broadly cuneate, apex prolonged-acuminate; primary pinnules ca. 15 pairs, stalked, lanceolate or oblong, basal basiscopic ones larger (to 14 × 4.5 cm), base cuneate, apex acuminate; secondary pinnules shortly stalked, ovate-oblong, to 3 × 1.5 cm, base cuneate, apex obtuse; tertiary pinnules ovate-oblong or oblong-rhombic, 8-10 × 5-6 mm, acroscopic base wider with poorly developed auriculate tip, basiscopic base cuneate, apex obtuse or acute, margin coarsely serrate or pinnatifid, lobes sharpened at apex, margins with 1(or 2) pairs of short teeth with poorly developed mucronate tip; upper pinnae gradually reduced; axes and veins of ultimate segments with a few minute blackish brown subulate scales abaxially. Sori small, terminal on veinlets, 1-3 pairs per ultimate pinnule, medial between midvein and margin; indusia dark brown, papery, entire.
● In ravines, on shaded wet rocks, forests; 500-1500 m. Guangdong, Guangxi, Guizhou, Taiwan.