杜氏耳蕨 du shi er jue

Aspidium duthiei C. Hope, J. Bombay Nat. Hist. Soc. 12: 532. 1899; Sorolepidium duthiei (C. Hope) Ching; Polystichum duthiei var. subbipinnatum Tagawa; P. tsuchuense Ching.

Plants summer-green. Rhizome erect, densely covered with broadly lanceolate brown scales, with persistent stipe bases. Fronds 5-12 cm; stipe stramineous, 1-3 cm, ca. 1 mm in diam. at base, lower part persistent, densely covered with narrowly ovate and lanceolate scales; scales light brown, serrulate. Lamina 1-pinnate, linear, 6-13 × 1-1.2 cm, slightly contracted at base, acuminate; rachis without proliferous bulbils, adaxially scaly, scales light brown, linear-lanceolate and hairlike, abaxially densely covered with same scales. Pinnae 16-25 pairs, alternate, attached at right angles to rachis, approximate, sessile, ovate or deltoid-ovate, middle pairs 6-7 × 4-5 mm, bases broadly cuneate or nearly rounded, auriculate acroscopically and basiscopically, margins with obtuse teeth or pinnatilobate, apices obtuse; abaxially with narrowly lanceolate light brown microscales, adaxially with hairlike white microscales; frond texture papery; venation pinnate on pinnules, indistinct on both surfaces. Sori on upper pinnae from middle of lamina upward, in 1 row on each side of midrib; indusia present, toothed.

Alpine meadows and rocks; 2800-4800 m. Gansu, Xizang, Yunnan [N and NW India, Nepal].

Polystichum duthiei is not distributed in Taiwan.