中越蹄盖蕨 zhong yue ti gai jue

Lunathyrium christensenii (Tardieu) Ching.

Rhizomes short, erect, apex densely scaly; scales dark brown, linear-lanceolate, fibriform-tipped. Fronds caespitose; fertile fronds 40-75 cm; stipe blackish brown, upward green-stramineous, 18-30 cm, 2-2.5 mm in diam. at base, base similarly densely scaly, upward with sparse small scales; lamina 2-pinnate, ovate-oblong, (28-)35-55 × 12-16 cm, base narrowed, apex acuminate; pinnae 15-20 pairs, basal pinnae subopposite, upper pinnae alternate, spreading or slightly ascending, with short stalk ca. 1.5 mm or subsessile, basal pinnae conspicuously shortened, broadly lanceolate, 10-12 × ca. 2 cm, base inequilateral, narrowly cuneate on basiscopic base, pinnate, apex acuminate; pinnules 8-12 pairs, alternate, slightly ascending, sessile, narrowly elliptic, ca. 1.2 cm × 4 mm, base adnate to costae, decurrent on basiscopic side, margin shallowly repand-lobed or crenate, apex rounded or obtuse-acute; middle pinnae larger, up to 13 × ca. 2.5 cm, base equilateral, subtruncate, pinnate, apex long acuminate, somewhat caudate; pinnules similar to pinnules of basal pinna, slightly larger; veins slightly visible adaxially, visible abaxially, pinnate in pinnules, lateral veins 6-8 pairs, basal veins forked (sometimes pinnate), upper veins simple. Lamina herbaceous when dried, light greenish brown, glabrate on both surfaces; rachis and costae on abaxial surface stramineous, with dense brown short glandular hairs, with subulate spines on adaxial side at base of costa or costule. Sori shortly linear or oblong, ca. 7 pairs per pinnule, biseriate on both sides of costules, medial or supramedial; indusia brown, shortly linear or oblong, membranous, entire, persistent. Perispore surface without folds, with granular ornamentation.

Evergreen forests; 1000-2300 m. SW Guangxi, SE Yunnan [Vietnam].