居中蹄盖蕨 ju zhong ti gai jue

Athyrium acutiserratum Ching.

Rhizomes short, erect, apex densely clothed with dark brown, linear-lanceolate scales. Fronds caespitose; fertile fronds 35-42 cm; stipe blackish brown, upward stramineous, shiny, 18-22 cm, base ca. 3 mm in diam., similarly densely scaly; lamina nearly 2-pinnate, ovate-oblong, 20-25 × 13-15 cm at middle, base slightly narrowed, apex acuminate; pinnae ca. 12 pairs, basal 1-3 pairs subopposite, upper pinnae alternate, spreading, sessile; basal pinnae shortened, 5.5-7 cm, base slightly narrowed; middle pinnae lanceolate, 7-8 × ca. 2 cm at middle, base equilateral, truncate alongside rachis, nearly pinnate, apex shortly acuminate; pinnules ca. 15 pairs, adnate to costae, oblong, 8-10 × 4-5 mm at middle, base decurrent and adnate to wing of costae, pinnatilobate or biserrate, apex obtuse; veins inconspicuous adaxially, visible on abaxial surface, pinnate in pinnules, lateral veins ca. 5 pairs, oblique, lower veins forked, upper veins simple. Lamina firmly herbaceous when dried, greenish brown, sometimes sparsely shortly hairy adaxially, glabrate abaxially; rachis and costae stramineous abaxially, glabrate or shortly hairy, with subulate spines on adaxial side at base of costa or costule, wing of costae shortly hairy at margin. Sori mostly oblong, slightly curved, sometimes J-shaped, inframedial on basal acroscopic veins, 4 or 5 pairs per pinnule; indusia pale brown, J-shaped, often horseshoe-shaped on basal acroscopic veins, membranous, ciliate at margin, persistent. Perispore surface without folds, with reticulate ornamentation, areoles unequal in size, ridges sometimes disconnected.

● Valley forests; 2700-3500 m. NW Yunnan.