矩圆双盖蕨 ju yuan shuang gai jue

Athyrium pseudosetigerum Christ, Bull. Acad. Int. Géogr. Bot. 17: 146. 1907; Allantodia pseudosetigera (Christ) Ching.

Plants evergreen, medium-sized. Rhizome ascending to erect, brown, ca. 1 cm in diam., densely scaly at apex; scales brown, ovate-lanceolate, 4-5 × 2-2.5 mm, thickly membranous, entire, apex long acuminate; fronds caespitose. Fertile fronds up to 60 cm; stipe brown at base, upward stramineous, 22-30 cm, ca. 2.5 mm in diam., base with sparse lanceolate brown scales, upward glabrous, shallowly grooved adaxially; lamina 2-pinnate with pinnatipartite pinnules, deltoid, ca. 30 × 22-25 cm at base, apex long acuminate; pinnae 15-18 × 9-12 cm, slightly narrowed to base, base cuneate, with stalk 1-1.5 cm; upper pinnae lanceolate, 1-pinnate, shortly stalked or sessile; pinnules 10-12 pairs, alternate, ascending, sickle-shaped lanceolate, 5-7 × 1-2 cm, base rounded-cuneate, with stalk 1-2 mm, apex long acuminate; basal pinnule lobes nearly free; pinnule lobes ca. 10 pairs, ascending, sessile, oblong, 8-10 × ca. 4 mm, basal 2 or 3 pairs of lobes connected to narrow wing, margin serrate, apex acute. Veins slightly impressed, raised on abaxial side, pinnate; veinlets 5 or 6 pairs per lobe, forked, ascending. Lamina herbaceous, brown-green when dry, glabrous on both surfaces; rachis and costa stramineous, glabrous, shallowly grooved adaxially. Sori 2 or 3 pairs per lobe, medial, oblong, 1-1.5 mm; indusia light brown, oblong, thinly membranous, vaulted when mature, irregularly ruptured on back. Spore reniform, perispore surface with irregularly aculeate, unevenly distributed projections.

At entrances of limestone caves; ca. 700 m. Chongqing, Guangxi, Guizhou [N and NE Vietnam (Liangshan)].