藏东南蹄盖蕨 zang dong nan ti gai jue

Athyrium aculeatum Ching; A. dajinense Ching.

Fertile fronds ca. 66 cm; stipe blackish brown, upward pale red-purple, 24-28 cm, 2.5-3.5 mm in diam. at base, base densely clothed with brownish, narrowly lanceolate scales, upward glabrate; lamina 2-pinnate, ovate-lanceolate, up to 40 × ca. 22 cm above base, base hardly narrowed, apex acuminate; pinnae ca. 15 pairs, basal pinnae opposite, upper pinnae alternate, subspreading or ascending, sessile; basal pinnae slightly shortened, up to 13 cm, base narrowed; middle pinnae narrowly lanceolate, up to 14 × ca. 3 cm at middle, base inequilateral, truncate, parallel to rachis on acroscopic side, broadly cuneate on basiscopic side, pinnate, apex acuminate; pinnules 15-17 pairs, basal pinnules subopposite, upper pinnules alternate, spreading, widely separated from each other, ovate-oblong, middle pinnules 1.2-1.5 cm × 6-7 mm at base, base inequilateral, rounded-truncate on acroscopic side, narrowly cuneate on basiscopic side, decurrent and adnate to wing of costae, pinnatifid to 1/2, apex obtuse-rounded or acute; pinnule segments 5 or 6 pairs, with 2 or 3 stretched teeth at apex; veins somewhat visible adaxially, visible abaxially, pinnate in pinnules, lateral veins 2- or 3-forked, sometimes pinnate in basal acroscopic segments. Lamina herbaceous when dried, dark green, with sparse short hairs adaxially; rachis and costae pale purplish red, with subulate short spines adaxially, wings of costae with short hairs at margin. Sori mostly elliptic, occasionally curved, 1 per segment, inframedial; indusia brown, elliptic, occasionally J-shaped, membranous, subentire, persistent. Perispore surface without folds.

● Coniferous forests; 2400-3800 m. Sichuan, SE Xizang, Yunnan.

Athyrium austro-orientale is very similar to A. suprapuberulum but differs by the stipes and rachis pale red-purple abaxially, lower pinnules separated from each other by 3-5 mm, and pinnule segments shortly toothed at apex.