线叶耳蕨 xian ye er jue

Plants evergreen. Rhizome ascending, 0.5-2.2 cm, 0.4-1.6 cm in diam. together with remnant bases of old stipes, scaly; scales similar to stipe scales but much darker; roots dull brown when dry, 0.16-0.28 mm in diam., subglabrous or occasionally covered with linear and tortuous scales, longer ones once or twice branched with lateral rootlets, up to 1.8 cm. Fronds 8-18(-25) per rhizome, appressed to substrate or ascending, (5.9-)11.2-16.8 cm; stipe green, (0.5-)1.5-4.8 cm, 0.31-1.18 mm in diam. at middle, densely covered with spreading scales; scales brown, ovate to lanceolate, 2.52-4.05 × 0.85-1.25 mm, thinly papery, bases rounded and slightly peltate, margins with 0.5-0.8 mm curled hairlike outgrowths, apices caudate and ending in a ca. 0.8 mm hairlike tip; mixed smaller scales (fewer and mostly adaxial) deltoid-lanceolate, ca. 2 × 0.5 mm, margins and apices with hairlike outgrowths, basal stipe scales mostly without marginal outgrowths and hairlike tips, thicker in texture and dark brown. Lamina 1-pinnate, linear, (4.5-)7.5-12.5 × 0.9-1.5 cm, ± narrowed toward base from below middle, apex acuminate; rachis 0.3-0.58 mm in diam. at middle, without proliferous bulbils, green (as in pinnae) when fresh, yellowish green when dry, abaxially densely covered with scales, adaxially sparsely scaly (especially at base of stalks); abaxial rachis scales ovate to broadly lanceolate, similar to those of stipe but smaller, lighter and thinner in texture; adaxial rachis scales dark brown, deltoid-subulate, up to 2 × 0.45 mm, hairlike outgrowths only at broadest base, subentire, caudate. Pinnae (16-) 25-55 pairs, alternate, 1-2 mm apart, approximate or imbricate (sometimes basal 1-6 pairs up to 3 mm apart, other pinnae imbricate), asymmetrically rectangular-oblong (or slightly falcate toward apex), 3.5-6.5 × 1.8-2.5 mm, lowest pairs usually 1/2-2/3 as long as middle pinnae, asymmetrically deltoid, or fan-shaped, shortly stalked (stalk up to ca. 1 mm, attached with rachis at an acroscopic angle of ca. 60°), basiscopic margins at angles of 75°-150° with rachis, base on acroscopic side cuneate, basiscopic side truncate (with a blunt auricle, sometimes auricle deeply incised to near midrib and forming a basal free cuneate-based lobe ca. 2 × 1.8 mm with 2 or more small teeth at apex), forming angles of 90°-120° at point where stalks attached, margins slightly cartilaginous, basiscopic side subentire, distally curved toward apex and with 1 or 2 small teeth (distal margins of some fronds curved with 2 or 3 undulations), acroscopic side with 3 or 4 shallow teeth between basal auricle teeth and pinna apex (sometimes this side also with 3 or more shallow or rarely deep undulations), apex rounded or acute (or acuminate) and ending in a blunt tooth, all teeth without aristate tips; adaxially glabrous (occasionally with 1-3 microscales), abaxially covered with microscales (especially along veins); microscales broad-type, light brown, oblong to narrowly ovate, 0.8-1.2 × 0.15-0.25 mm, membranous, margins irregularly erose, apices hairlike, broadest part consisting of 6-8 lines of cells; frond texture thinly leathery; venation pinnate, visible abaxially, indistinct adaxially; lateral veins free, simple or once forked. Sori terminal on lateral veins, 2-4(or 5) on acroscopic side, none or 1 on distal basiscopic side, 1.4-2.4 mm in diam., mostly medial (between pinna margins and midrib), proximal 1 or 2 sori closer to pinna margin, occasionally all sori close to pinna margin, centers ca. 1.5 mm apart from one another, approximate when mature; indusia absent.

● Shaded or unshaded damp limestone cliffs of small gorges, carbonate sediments at bottom of cave mouths; 1100-1300 m. N Guizhou (Zunyi).