大关耳蕨 da guan er jue

Plants evergreen. Rhizome erect, short. Fronds 18-30 cm; stipe pale greenish stramineous, 2.5-7 cm, ca. 1 mm in diam. at base, upper stipe base to rachis sparsely scaly; scales dark brown, often appressed, ovate, membranous, with irregular fine teeth. Lamina 1-pinnate, narrowly elliptic-lanceolate, 10-27 × 1.5-2.5 cm at middle, truncate or slightly broadly cuneate, nearly shallowly cordate, acuminate; rachis pale greenish stramineous, without proliferous bulbils. Pinnae 20-40 pairs, alternate or nearly opposite, slightly angled acroscopically or attached at right angles with rachis, approximate to contiguous, sessile, nearly rectangular, middle pairs 7-15 × 2-4 mm, basal pairs 5-10 × 2-4 mm, apices acute, bases asymmetrical, acroscopic base with deltoid auricles, proximal acroscopic margins of pinnae parallel with rachis, acroscopic margins substraight, basiscopic base narrowly cuneate, distal basiscopic margins curved, acroscopic margins of pinnae with 11-13 regular coarse teeth, only ca. 1/3 of basiscopic margins of pinnae serrate and with 3 teeth, teeth shortly spinulose and forward-pointing or slightly recurved; adaxially glabrous, abaxially sparsely scaly; microscales light brown, appressed, ovate or lanceolate, membranous; frond texture papery; venation distinct on both surfaces, pinnate, lateral veins often dichotomous above midrib, simple below midrib, veinlets nearly reaching pinna margin. Sori relatively large, contiguous or nearly so when mature, terminal on shorter veinlets, close to pinna margin, 1-5 above midrib, 1 or 2 below midrib and on apical part, auricles and lower part of basiscopic margins without sori; indusia present, light brown, subentire, persistent. Spores orbicular in equatorial view; perispore sculpturing plicate with granules.

● Wet rock crevices in bushes in limestone valleys; 1500-2000 m. NE Yunnan (Daguan, Yongshan).