55. Diplazium leptophyllum Christ in C. Christensen, Index Filic., Suppl. 1: 103. 1916.
卵叶双盖蕨 luan ye shuang gai jue
Asplenium leptophyllum Baker, Bull. Misc. Inform. Kew 1906: 10. 1906, not Swartz (1791), nor Lagasca (1802), nor Fée (1857); Allantodia leptophylla (Christ) Ching.
Plants evergreen, medium-sized. Rhizome creeping, densely scaly; scales black, linear-lanceolate, ca. 1 cm, entire, apex filiform, slightly curly; fronds approximate. Fertile frond up to 1 m; stipe brown at base, upward stramineous, ca. 40 cm, base sparsely scaly, upward subglabrous; lamina 2-pinnate with pinnules pinnatipartite, deltoid-ovate, up to ca. 50 × 45 cm at base, apex acuminate; pinnae up to 8 pairs, alternate, spreading, lower pinnae 8-10 cm apart; basal pinnae broadly lanceolate, up to 35 × 12 cm, base crenate, with stalk up to 5 cm, apex acuminate; pinnules up to 12 pairs, alternate, slightly ascending, sickle-shaped lanceolate, ca. 10 × 3 cm, base shallowly cordate, with stalk up to 8 mm, pinnatipartite, apex acuminate; pinnule lobes up to 10 pairs, oblong, up to 2 × 1.4 cm, margin dentate or shallowly pinnatifid, apex obtuse; basal lobes largest, basiscopic lobe ovate-oblong, nearly pinnatifid; veins prominent, pinnate, veinlets 5 or 6 pairs per each lobe, 2- or 3-furcate, ascending. Lamina herbaceous, yellow-green when dry, glabrous on both surfaces; rachis and costae stramineous, glabrous, shallowly grooved adaxially. Sori linear, 4-6 mm, 6 or 7 pairs per lobe, inframedial, from midrib to near lobe margin, usually double or forked; indusia light brown, linear, membranous, persistent. Spores bean-shaped, perispore indistinguishable, with dense aculeate ornamentation on surface.
Evergreen broad-leaved forests; 1200-1500 m. S and W Yunnan (Longling, Menghai, Tengchong) [Bhutan, Myanmar, N Thailand].
The type specimen is A. Henry 13106, recorded as collected from Simao ("Szemao"), S Yunnan, but most likely collected from Xishuangbanna, Menghai. This species is very common in Menghai under secondary mixed broad-leaved coniferous forests and evergreen broad-leaved forests at elevations as high as Henrys record (5000 ft. = 1524 m).
