欧亚铁角蕨 ou ya tie jiao jue

Asplenium ramosum Linnaeus, nom. utique rej.

Plants small, 8-15 cm tall. Rhizome erect or ascending, short, apex scaly; scales black, narrowly triangular, often with glandular appendages at base. Fronds caespitose; stipe reddish brown or castaneous only at base, upward green, 2-6 cm, with dark brown narrow scales or subglabrous; lamina linear, 6-15 × 1-1.3 cm, base reduced, apex acute, 1-pinnate; pinnae 14-20 pairs, rhombic-ovate to orbicular, stalked, basal pinnae opposite, upper pinnae alternate, middle pinnae 4-6 × 4-6 mm, margins crenate to (sometimes) deeply incised, apex obtuse, lower 2 or 3 pairs reduced and gradually deltoid, base subtruncate. Vein pattern obscure, anadromously pinnate, veins simple or forked, not reaching margin. Fronds herbaceous, green; rachis green, adaxially longitudinally grooved. Sori 4-8 per segment, linear, 1-1.5 mm, confluent at maturity; indusia greenish white, semi-elliptic, membranous, entire or slightly toothed, opening toward costa and persistent. Spores with average exospore length 30-33 µm, perispore lophate (alate). Plants sexual diploid: 2n = 72.

In crevices of calcareous, dolomitic, or serpentine rocks; 3300-4500 m. Sichuan, Taiwan, Xinjiang, Xizang [Afghanistan, India, Japan, Kashmir, Nepal, Pakistan, Russia; Europe, North America].