裸果耳蕨 luo guo er jue

Plants evergreen. Rhizome erect or ascending, short, densely covered with linear brown scales. Fronds 30-100 cm; stipe yellowish brown, 9-47 cm, 3-7 mm in diam. at base, densely covered with linear, lanceolate, brown scales and larger scales; large scales dense, brown and bicolorous, ovate and ovate-lanceolate, middle of bicolorous scales blackish brown and margins brown, shiny, up to 12 × 6 mm, subentire or serrulate, caudate. Lamina bipinnate, oblong-lanceolate or oblong, 22-85 × 6-20 cm near base, not or slightly contracted toward base, base sterile, apex caudate, fertile; rachis without proliferous bulbils, abaxially densely covered with linear and lanceolate, brown scales and larger scales; large scales sparse, brown, ovate-lanceolate and broadly lanceolate, up to 10 × 4 mm, densely serrulate, long acuminate. Pinnae 21-39 pairs, alternate, slightly ascendant, shortly stalked, lanceolate, not contracted toward base, bases asymmetrical, apices caudate; lower pinnae 5-10 × 1.4-2 cm, 1-pinnate; costa abaxially covered with linear brown scales, adaxially sulcate. Pinnules 13-38 pairs, alternate, subsessile, oblong, 0.4-1 × 0.2-0.5 cm, bases cuneate, acroscopic margins entire, not spinulose, bases exauriculate, basiscopic margins shortly spinulose, apices acute and mucronate; basal acroscopic pinnules largest, margins incised; both surfaces densely covered with long-filiform microscales; frond texture papery; venation pinnate, lateral veins 5-7 pairs, dichotomous, distinct. Sori small, caducous, (1 or)2-5 pairs per pinnule, in 1 row on each side of midrib, close to midrib, terminal on veinlets, exindusiate.

● Mixed broad-leaved and coniferous forests, forest margins; 1800-3000 m. Xizang (Mêdog), Yunnan.

Polystichum nudisorum differs from P. longipaleatum in its bicolorous stipe scales. It has narrower and higher distribution than P. longipaleatum.

This species might also occur in N India.