元阳蹄盖蕨 yuan yang ti gai jue

Rhizomes somewhat ascending, apex densely clothed with brown, lanceolate scales. Fronds caespitose; fertile fronds up to 65 cm; stipe brown, upward pale green-stramineous, up to 28 cm, ca. 3 mm in diam. at base, base similarly densely scaly, upward with sparse small scales; lamina 2-pinnate, ovate, up to 38 × ca. 28 cm, base rounded, apex abruptly narrowed; pinnae under abruptly narrowed tip 6(or 7) pairs, alternate, stalked (stalk 2-3 mm), ascending, basal pinnae hardly shortened, base not narrowed, second basal pinnae lanceolate, up to 18 × ca. 5 cm at base, base subequilateral, truncate, pinnate, apex caudate-long-acuminate; pinnules ca. 15 pairs, alternate, spreading, with short stalk 1-1.5 mm, basal acroscopic pinnules nearly pinnate, others pinnatipartite; basal acroscopic pinnule segments larger, obovate, with short teeth at margin; veins visible abaxially, somewhat visible adaxially, pinnate in segments, lateral veins 2-4 pairs, oblique, forked or simple. Lamina herbaceous when dried, green, glabrate on both surfaces; rachis and costae pale stramineous, densely shortly hairy abaxially, with needlelike spines on adaxial side at base of costa, costule, and midrib. Sori elliptic or oblong, on basal acroscopic veins, 1 per segment (but 1 or 2 pairs in basal acroscopic 1(or 2) segment), biseriate on both sides of costules (or midribs), subcostular; indusia brown, elliptic or oblong, membranous, subentire, persistent. Perispore surface without folds.

● Mossy forests; ca. 2600 m. S Yunnan (Yuanyang).

Athyrium yuanyangense is similar to A. clivicola in frond appearance but differs by the fronds larger (to 65 cm); pinnules more (ca. 15 pairs), more dissected (pinnatifid); basal acroscopic pinnules much larger, obovate, almost free; costae more shortly pubescent abaxially; and needlelike spines on the adaxial side at the base of costa, costule, and midrib.