69. Athyrium zayuense Z. R. Wang, Acta Phytotax. Sin. 32: 84. 1994.
察隅蹄盖蕨 cha yu ti gai jue
Rhizomes short, erect, apex densely scaly; scales chestnut-black in central part, dark brown in marginal part, linear-lanceolate, fibriform-tipped. Fronds caespitose; fertile fronds 38-40 cm; stipe stramineous, 12-14 cm, 1-1.5 mm in diam., base densely scaly, upward subglabrate; lamina 2-pinnate, ovate-oblong, ca. 28 × 11-12 cm at middle, base hardly narrowed, apex long acuminate; pinnae ca. 15 pairs, sessile, lower pinnae subopposite, upper pinnae alternate, basal 1-3 pairs of pinnae slightly shortened, reflexed, base slightly narrowed, but slightly prominent, subspreading-ascending, linear-lanceolate, 5-6 cm × 9-10 mm at middle, base truncate, equilateral, pinnate, apex long acuminate; pinnules ca. 15 pairs, lower pinnules opposite, upper pinnules alternate, spreading, oblong, 3-4 × 2-2.5 mm at base, base subequilateral, decurrent and adnate to wing of costa, somewhat auriculate on acroscopic side, margin biserrate, apex rounded-truncate and toothed; veins visible abaxially, pinnate in pinnules, lateral veins ca. 5 pairs, oblique, forked. Lamina herbaceous when dried, greenish brown, glabrate on both surfaces; rachis and costae stramineous, with brownish short glandular hairs abaxially, margin of wings sparsely hairy, with subulate spines on adaxial side at base of costa or costule. Sori oblong, ca. 3 pairs per pinnule, basal acroscopic sori often J-shaped; indusia pale brown, oblong or J-shaped, membranous, erose, persistent. Spores bilateral, perispore surface without folds.
● Coniferous forests on mountain slopes; 3300-3400 m. SE Xizang (Zayü).
Athyrium zayuense is very similar to A. dubium in appearance but differs by the pinnae and segments much smaller, pinnae less than 1 cm wide, pinnules oblong, subtruncate, 2-3 mm wide, and scales at stipe base black in central part with prominent brown narrow margin.
The name "Athyrium chayuense" (Z. R. Wang, Vasc. Pl. Hengduan Mount. 1: 84. 1993) was not validly published because no Latin description or diagnosis, or reference to such, was provided (Melbourne Code, Art. 39.1).