22. Adiantum fengianum Ching, Bull. Fan Mem. Inst. Biol., n.s. 1: 267. 1949.
冯氏铁线蕨 feng shi tie xian jue
Plants ca. 10 cm tall. Rhizomes decumbent, slender, scales dense, dark brown. Fronds approximate; stipe dark castaneous, glossy, 3-6 cm, as slender as silk, smooth above base; lamina 2-pinnate, narrowly ovate to lanceolate in outline, 3-5 × 1-2 cm, apex obtuse; pinnae 4 or 5 each side, horizontally or obliquely spreading; rachises, costae, and stalks same as stipe; pinnae below middle only, ± uniform in size, imparipinnate, narrowly ovate in outline, 1-1.5 × ca. 0.8 cm; pinnules alternate, with short, slender stalks, spreading obliquely upward, uniformly obtriangular, ca. 4 mm, progressively slightly smaller distally, herbaceous, green, both surfaces glabrous, sterile pinnules: base symmetrically cuneate, bilateral margins straight and entire, upper margins divided and sharply serrate, apex rounded, fertile pinnules with apex truncate or with few sharp serrations on bilateral acroscopic corner; veins multidichotomously forked and reaching margins, visible on both surfaces. Sori 1 per pinnule, horizontally attached at upper margin; false indusia glaucous or dark brown, elongate, nearly as wide as upper margin of pinnule, membranous, upper margins truncate or slightly undulate, persistent. Perispore indistinctly granular.
● Wet rocks in forests; ca. 3400 m. N Yunnan (Lijiang, Yulong Shan).
Adiantum fengianum is listed as endangered in the IUCN Red Book (China Plant Specialist Group 2004. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. ; accessed 16 Apr 2013).