31. Adiantum roborowskii Maximowicz, Mélanges Biol. Bull. Phys.-Math. Acad. Imp. Sci. Saint-Pétersbourg. 11: 867. 1883.
陇南铁线蕨 long nan tie xian jue
Plants epilithic, 9-25(-35+) cm tall. Rhizomes erect or ascending, short, scales dense, dark brown, margins entire. Fronds clustered or approximate; stipe reddish castaneous, glossy, 2-20 cm, terete, base covered with same scales as rhizome, distally glabrous; lamina 3-pinnate on lower part, 1-pinnate on upper part, lanceolate or ovate-elliptic in outline, 2-18 × 2-6 cm, apex acuminate, pinnae 3-6 each side, all parts obliquely ascending, stalk 3-6 mm; rachises, costae, and stalks reddish castaneous, glabrous; basal pair of pinnae slightly larger, 2-pinnate, ovate-triangular, 1.5-3 × 1.2-1.4 cm, base rounded-cuneate, apex obtuse; distal pinnae progressively smaller, 1-pinnate; pinnules 1 or 2 pairs per pinna, alternate; stalk reddish castaneous, short, slender; blade subtriangular, narrowly flabellate, triangular, broadly ovate, or suborbicular-flabellate, 5-9 × 4-7 mm, papery or nearly hard papery, gray-green, both surfaces glabrous, base broadly or rounded cuneate, sterile pinnules with upper margins rounded and with slightly undulate projection; upper margins of fertile pinnules entire and with 1 or 2 deep sinuses at middle. Veins multidichotomously forked, nearly reaching margins, visible on both surfaces. Sori 1 or 2 per pinnule, in deep sinuses of upper margin; false indusia dark brown, orbicular or orbicular-reniform, subleathery, upper margins deeply sinuate, entire, persistent.
● In rock crevices in wet forests, on moss-covered or damp rocks and cliffs, on rocks or cliffs by ditch sides; 1000-3500 m. Gansu, Guizhou, Hubei, Qinghai, Shaanxi, Sichuan, C and S Taiwan, Xizang.