Aspidium biaristatum Blume, Enum. Pl. Javae 2: 164. 1828; A. aculeatum (Linnaeus) Swartz var. biaristatum (Blume) C. B. Clarke; Polystichum aculeatum (Linnaeus) Roth ex Mertens var. biaristatum (Blume) Beddome; P. aculeatum var. durissimum Rosenstock; P. subapiciflorum Hayata.

Plants evergreen. Rhizome erect or ascending, short, densely covered with linear brown scales. Fronds up to 1 m; stipe stramineous, 50-58 cm, ca. 6 mm in diam. at base, with linear and lanceolate brown scales and larger scales; large scales denser on lower stipe, bicolorous, middle part blackish brown, margins brown, shiny, ovate-lanceolate, up to 21 × 10 mm, subentire, caudate. Lamina bipinnate, deltoid-oblong, 57-61 × 27-29 cm at middle, slightly contracted toward base, acute; rachis and costa without proliferous bulbils, densely covered with linear dark brown scales and subulate scales, subulate scale margins fimbriate. Pinnae 8-12 pairs, alternate, ascendant, shortly stalked, lanceolate, 12-14 × 2.5-2.8 cm, 1-pinnate, apices caudate-acuminate and fertile, not contracted toward base. Pinnules 14-18 pairs, alternate, shortly stalked, oblong, 1.5-2(-3) × 0.6-0.8 cm, cuneate, acute; auricles deltoid, shallowly obtusely toothed, basal acroscopic pinnules largest; abaxially with few lanceolate microscales, adaxially subglabrous; frond texture thinly leathery; venation pinnate on pinnules, lateral veins 5-8 pairs, dichotomous, distinct. Sori dark brown, 6-8 pairs per pinnule, in 1 row on each side of midrib, terminal on veinlets, abaxial pinnule surface with sori obviously concave; indusia brown, membranous, entire.

Polystichum biaristatum has been reported as being much more widely distributed due to misidentification.

This species has laminae acute, rachis scales linear and subulate and brown, pinnae approximate, pinnules 1.5-2(-3) cm and toothed, and microscales lanceolate.

Wet places in forests; 1100-2200 m. Taiwan [Indonesia, Myanmar, Philippines, Singapore, Sri Lanka, Thailand, Vietnam].