翅柄铁线蕨 chi bing tie xian jue

Adiantum alatum Copeland; A. balansae Baker; A. caudatum Linnaeus var. soboliferum (Wallich ex Hooker) Beddome; A. dolabriforme Hooker; A. mettenii Kuhn; A. lunulatum N. L. Burman var. mettenii (Kuhn) Beddome.

Plants ?terrestrial, 25-30 cm tall. Rhizomes erect, short, scales dark brown, linear-lanceolate, margins entire. Fronds clustered; stipe castaneous-black, glossy, 9-16 cm, each side with a narrow brown membranous wing, base with same scales as rhizome, distally glabrous; lamina 1-pinnate, lanceolate in outline, 9-20 × 3.5-5.5 cm; rachis and stalks similar to stipe, apex of usually sterile rachis prolonged into whiplike stolon and rooting to form new plantlets; pinnules 5-10 pairs, alternate; stalk 2-4 mm, articulate, persistent after pinnules fall; basal 1 or 2 pairs of pinnules slightly reflexed, pinnules below middle uniform in size, horizontally spreading, dimidiate, suboblong, 2-3.3 × 0.9-1.4 cm, papery, brownish green, both surfaces glabrous, base asymmetrically broadly cuneate, lower and inner margins nearly flat and straight, upper and outer margins obtuse and 4-6-lobed; distal pinnules similar but slightly smaller; terminal pinnules flabellate, outer margin with 3-6 sinuses; veins multidichotomously forked, reaching cartilaginous margins, visible on both surfaces. Sori 3-7 per pinnule; false indusia dark brown, elliptic or reniform, papery, upper margins flat and straight, entire, persistent. Perispore granular. 2n = 120.

Wet forest soils; 100-700 m (in Taiwan). Guangdong, Guangxi, Hainan, Taiwan, N Yunnan [India, Indonesia, Nepal, Philippines, Vietnam; tropics and subtropics of N Africa and Asia].