58. Athyrium hirtirachis Ching & Y. P. Hsu, Fl. Tsinling. 2: 215. 1974.
毛轴蹄盖蕨 mao zhou ti gai jue
Athyrium gonggaense Z. R. Wang & Li Bing Zhang.
Rhizomes short, erect, apex densely clothed with dark brown, membranous, linear-lanceolate scales. Fronds caespitose; fertile fronds up to 65-106 cm; stipe pale stramineous, 30-40 cm, 3-4 mm in diam. at base, base similarly densely scaly, upward glabrate; lamina 2-pinnate-pinnatipartite, oblong or deltoid-oblong, 33-61 × (7-)22-46 cm at base, base slightly narrowed or almost not narrowed, apex acuminate; pinnae (8-) 14-18 pairs, basal 1 or 2 pairs subopposite, upper pinnae alternate, ascending, shortly stalked (stalk ca. 3 mm), oblong-lanceolate to lanceolate, basal pinnae slightly narrowed at base, pinnules anadromous; upper pinnae not narrowed or broadened at base, pinnules catadromous; middle pinnae (3.5-)13-22 × (1.5-)4-6 cm at middle, base subequilateral, truncate or somewhat auriculate on acroscopic side, cuneate on basiscopic side, pinnate, apex long acuminate to somewhat caudate; pinnules (5-)14-22 pairs, lower pinnules opposite, upper pinnules alternate, oblong to deltoid-ovate; middle pinnules 1.8-2.2 cm × ca. 7 mm, sessile, spreading or slightly ascending, base inequilateral, auriculate on acroscopic side, cuneate on basiscopic side, dentate or pinnatilobate to 1/2 at margin, apex obtuse-rounded to obtuse; pinnule segments 5 or 6 pairs, oblong, dentate at apex; veins visible abaxially, slightly visible adaxially, pinnate in pinnules, lateral veins 3-6 pairs, oblique, 2-4 veins forked per segment. Lamina herbaceous when dried, pale green; rachis and costae stramineous, slightly purplish red, with sparse brownish short hairs abaxially, hairs rather dense on middle and lower parts of costae on abaxial side, short hairs sparse on margin of costa wings, costules, and veins, with subulate spines on adaxial side at base of costa or costule. Sori oblong, elliptic, shortly linear, or J-shaped, sometimes horseshoe-shaped, 1-3 mm, 4-6 pairs per pinnule, biseriate on both sides of costule, 1 per segment, inframedial on basal acroscopic veins, often 2-4 on basal acroscopic pinnule segments; indusia brown, oblong, elliptic, or shortly linear, sometimes horseshoe-shaped, rarely J-shaped, membranous, erose at margin, persistent. Perispore surface without folds.
● Forests; 1800-3200 m. SE Gansu, Sichuan.
Athyrium hirtirachis morphologically is intermediate between A. mackinnonii and A. dubium. It differs from the former in the distal part of costae rather densely shortly hairy abaxially and the margin of wings ± hairy. It also differs from the latter in the pinnae shortly stalked, the lowest pinnae broader, the sori longer, and the scales at stipe base linear-lanceolate.