东南铁角蕨 dong nan tie jiao jue

Asplenium formosanum Baker; A. hancockii Baker (1885), not Maximowicz (1883).

Plants 15-20 cm tall. Rhizome erect, short, scaly; scales dark brown, narrowly triangular, subentire. Fronds caespitose; stipe green or base brownish gray, 4-10 cm, adaxially sulcate, with small reddish brown narrowly triangular scales or subglabrous; lamina ovate-triangular, 6-10 × 3-4 cm, apex acute, pinnate-pinnatisect to almost bipinnate; pinnae 5-9 pairs, subopposite or alternate, stalk 2-3 mm, basal pinnae not reduced, rhombic, 1.8-3 × 1-2 cm, base slightly asymmetrical, broadly cuneate, apex subacute; segments 1 or 2 pairs, elliptic, 3-11 × 2.5-5 mm, basal acroscopic lobe largest, base decurrent on costa, crenate to sinuate, apex obtuse to truncate. Costa shallowly grooved adaxially, veins anadromously forking. Fronds leathery, dark green when dry; rachis grayish stramineous or green, sulcate adaxially, with dark brown, narrowly triangular scales, subglabrous when old. Sori 1-4 per segment, median to distal on subtending veins, not reaching margin, oval-linear, 3-5 mm; indusia brown, oval-linear, membranous, entire, opening toward costa, persistent.

● On wet or moss-covered rocks in forests; 100-900 m. Anhui, Fujian, Jiangxi, Taiwan, Zhejiang.

The relationship of Asplenium oldhamii to A. austrochinense requires further study.