Description from Flora of China
Adiantum fimbriatum var. shensiense (Ching) Ching & Y. X. Lin; A. smithianum (C. Christensen) Ching; A. smithianum var. shensiense Ching; A. venustum D. Don var. smithianum C. Christensen.
Plants terrestrial or epilithic, (10-)25-35 cm tall. Rhizomes creeping, slender, scales dense, brown, glossy, ovate-lanceolate. Fronds spaced; stipe reddish castaneous, glossy, 10-20 cm, base covered with same scales as rhizome, distally glabrous; lamina 3- or 4-pinnate, ovate-triangular in outline, 7-25 × 10-20 cm, apex obtuse; pinnae 3-7 each side, oblique upward, stalks ca. 10 mm; rachises, costae, and stalks zigzag, same color as stipes, glossy, basal pair of pinnae largest, 2-pinnate, ovate-triangular in outline, 6-10 × 4-8 cm, apex obtuse; distal pinnae 1-pinnate; pinnules 3-5 pairs per ultimate pinna, stalked, obovate or flabellate, 6-7 × 6-7 mm or longer than wide, progressively smaller distally, thinly herbaceous, greenish or gray-green, both surfaces glabrous, base symmetrical or slightly oblique, cuneate, bilateral sides entire, apex rounded or ± oblique, with dense small sharp narrowly triangular teeth without awned tips. Veins flabellately forked, ending in marginal teeth, visible on both surfaces. Sori (1 or)2 or 3(-5) per pinnule; false indusia brownish, rectangular, reniform, orbicular, or orbicular-reniform, membranous, less often slightly depressed, upper margins more often flat and straight, entire, persistent. Perispore indistinctly granular.
● On rocks or in rock crevices in forests by streamsides; 2700-3600 m. Gansu, Hebei, Qinghai, Shaanxi, Shanxi, Sichuan, Xizang, Yunnan.