半育耳蕨 ban yu er jue

Aspidium aculeatum (Linnaeus) Swartz var. semifertile C. B. Clarke, Trans. Linn. Soc. London, Bot. 1: 509. 1880; Polystichum aculeatum (Linnaeus) Roth ex Mertens var. semifertile (C. B. Clarke) Beddome; P. nyalamense Ching; P. yunnanense Christ var. submuticum C. Christensen.

Plants evergreen. Rhizome erect or ascending, short, densely covered with linear brown scales. Fronds 60-100 cm; stipe brown, 26-60 cm, 4-7 mm in diam. at base, densely covered with linear, lanceolate and larger scales; large scales bicolorous, blackish brown at middle, shiny, ovate or ovate-lanceolate, up to 30 × 10 mm, subentire, caudate. Lamina bipinnate, oblong-ovate, 45-68 × 13-40 cm near base, lower part slightly contracted, fertile, apex abruptly narrowed, sterile; rachis without proliferous bulbils, abaxially sparsely or densely scaly; scales brown, lanceolate or linear, rachis scales of some individuals blackish, subentire or sparsely toothed, acuminate. Pinnae 14-25 pairs, alternate, attached at right angles to rachis, shortly stalked, lanceolate, lower part not contracted, bases asymmetrical, apices caudate or acuminate; pinnae near lamina base 8-26 × 2-3.8 cm, 1-pinnate; costa abaxially covered with linear light brown to brown scales; scales of basal costa lanceolate. Pinnules 10-20 pairs, alternate, shortly stalked, deltoid or oblong, 1-2.3 × 0.5-1 cm, bases cuneate, with rounded auricles acroscopically, margins entire to lobed, spinulose, apices acute; basal acroscopic pinnules largest, pinnatipartite; abaxially sparsely covered with shortly filiform microscales; frond texture thinly leathery to papery; venation pinnate, lateral veins 5-10 pairs, dichotomous, relatively distinct. Sori large, 6-8 pairs per pinnule, in 1 row on each side of midrib, close to midrib, terminal on veinlets; indusia present, spinulose-lacerate. 2n = 82.

Broad-leaved forests, mixed forests, mossy forests on montane slopes, valleys; 1000-3000 m. Sichuan (Shimian, Yanbian), Xizang (Mêdog, Nyalam) [India, Myanmar, Nepal, Thailand, Vietnam].