团羽铁线蕨 tuan yu tie xian jue

Adiantum cantoniense Hance.

Plants epilithic, 8-20 cm tall. Rhizomes erect, short, scales dark brown, lanceolate, margins entire. Fronds clustered; stipe dark castaneous, glossy, 2-6 cm, as slender as iron wire, base covered with same scales as rhizome, distally glabrous; lamina 1-pinnate, lanceolate in outline, 8-15 × 2.5-3.5 cm; costae and stalks castaneous, apex usually prolonged into a whiplike stolon and rooting to form new plantlets; pinnules 4-8 pairs, lower pinnules opposite, upper ones subopposite, spreading obliquely upward; stalk 2-3 mm, articulate, persistent after pinnules fall; lower several pairs of pinnules subequal in size, orbicular-flabellate or orbicular, 1.1-1.6 × 1.5-2 cm, membranous, green, both surfaces glabrous, base symmetrically rounded-cuneate or rounded, lateral sides entire, upper margins rounded, upper margin of sterile pinnules denticulate; fertile pinnules with 2-5 shallow sinuses, denticulate on sterile parts; distal and terminal pinnules similar to lower pinnules but smaller; veins multidichotomously forked, reaching margins, visible on both surfaces. Sori 1-5 per pinna; false indusia brown, orbicular or reniform, papery, upper margins flat and straight, persistent. Perispore granular.

Gregarious on wet limestone, basal crevices of walls, shaded wet chalky soil; 300-2500 m. Gansu, Guangdong, Guangxi, Guizhou, Hebei, Henan, Shandong, Sichuan, Taiwan, Yunnan [Japan, Korea].