7. Adiantum caudatum Linnaeus, Mant. Pl. 308. 1771.
鞭叶铁线蕨 bian ye tie xian jue
Adiantum caudatum var. angustilobatum Bonaparte; A. lyratum Blanco.
Plants terrestrial or epilithic, 10-40 cm tall. Rhizomes erect, short, scales deeply castaneous, lanceolate, margins entire. Fronds clustered; stipe castaneous, 1-10 cm, densely dark brown or brownish multicellular hirsute; lamina 1-pinnate, lanceolate in outline, 15-30 × 2-4 cm, base slightly narrow; rachis same color as stipe and similarly sparsely hirsute, glabrescent when old, apex usually prolonged into a whiplike stolon rooting at tip to form new plantlet; pinnules 20-44 pairs, 5-8 mm apart, alternate, or lower ones subopposite, horizontally spreading or slightly obliquely spreading, lower pinnules gradually reduced, middle ones ± dimidiate, suboblong, 0.7-2 × 0.6-1 cm, papery, brownish green, both surfaces sparsely multicellular hirsute and densely pubescent, base asymmetrical, lower margins substraight and entire, upper and outer margins deeply divided into many narrow lobes, upper side truncate; lobes linear, margins entire, upper part again lobed into fine linear segments, apex truncate, fine segments truncate or few dentate at apex; veins multidichotomously branching, visible on both surfaces. Sori 5-12 per pinna; false indusia dark brown, orbicular or oblong, hairy, upper margins flat and straight, entire, persistent. Perispore granular. 2n = 90.
On rocks or in rock crevices in forests or mountain valleys; 100-1200 m. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Taiwan, Yunnan [Bhutan, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Philippines, Thailand, Vietnam; throughout Old World tropics].