Trichomanes apiifolium C. Presl, Hymenophyllaceae, 16, 44. 1843; Cephalomanes apiifolium (C. Presl) K. Iwatsuki.

Plants 30-40 cm tall. Rhizome densely covered with multicellular long reddish brown hairs at apex, with dense wirelike roots at base. Stipe dark brown, 8-13 cm × ca. 1.5 mm, with dense multicellular long hairs, hairs caducous. Rachis dark brown, slightly zigzag, covered with reddish brown multicellular long hairs, narrowly winged in upper part. Lamina ovate-lanceolate, 20-30 × 8-10 cm, apex acuminate; pinnae ca. 15 pairs, closely spaced or slightly imbricate to neighboring ones, alternate, shortly stalked, spreading, oblong-lanceolate, 3-5 × 1-2 cm, base unequally cuneate, apex obtuse, lower pinnae usually slightly shortened; pinnules 5-8 pairs, often 1-2 mm apart, alternate, subsessile, ovate, oblique, 8-10 × 4-6 mm, base unequally cuneate, apex obtuse; ultimate segments on axis at angles of 10º-20º, closely spaced, 3-5 × 0.5-0.7 mm, with a single veinlet, margin entire, apex rounded. Veins dichotomous, dark brown, stout, obviously raised on each surface, glabrous. Sori on upper parts of frond; involucres obconic, ca. 1 × 0.6 mm, wingless, lobes sharply constricted below base of involucre, not or slightly dilated at mouth; receptacles brown. 2n = 72.

Usually near streams in dense forests, mountain forests; low elevations to 1500 m. Hainan, Taiwan [Japan (Ryukyu Islands), Malesia, Thailand, Vietnam; Pacific islands (Melanesia, Micronesia, Polynesia)].