Drynaria sect. Lepisorus J. Smith, Bot. Mag. 72. Comp. 13. 1846; Belvisia Mirbel; Drymotaenium Makino; Hymenolepis Kaulfuss (1824), not Cassini (1817); Macroplethus C. Presl; Platygyria Ching & S. K. Wu.

Plants epiphytic or epilithic, rarely terrestrial. Rhizomes creeping, ± terete or slightly flattened, densely scaly when young, sometimes naked when old, sometimes with white waxlike covering; scales blackish brown, opaque or clathrately transparent, ovate, orbicular, or broadly lanceolate to subulate-lanceolate, entire to deeply serrate. Fronds simple, remote or closely spaced, monomorphic, less often ± dimorphic; stipe usually short, base sparsely scaly, upper part smooth, mostly straw-colored, less often dark brown; lamina mostly lanceolate, less often narrowly lanceolate to linear or auriculate to pedately lobed, margin entire or undulate, often revolute when dried, mostly leathery or papery, less often herbaceous when dried, both surfaces glabrous or abaxially sparsely scaly. Midrib obvious, lateral veins often obscure, veinlets reticulate, areoles with simple or forked included veinlets, sometimes with hydathodes at ends. Sori large, orbicular or elliptic, sometimes confluent into linear coenosori, in 1 row on each side of midrib, superficial or sometimes deeply impressed, covered with paraphyses when young; paraphyses peltate, entire or denticulate, less often stellate or scalelike, often brown at center, pale at margin; lumina large, transparent. Sporangia usually leptosporangiate: long stalked, subpyriform, annulus longitudinal, consisting of 14 conspicuously thickened cells; less often sporangia platygyroid: subspherical, annulus of much wider thin-walled cells. Spores ellipsoid, without perispore, surface mostly rugose or undulate, less often smooth, tuberculate, or foveolate. 2n = 39, 46, 50, 52, 70, 74, 94, 95, 100, 148, 150.

The type species is Lepisorus nudus (Hooker) Ching (Pleopeltis nuda Hooker, described from Nepal), not, as sometimes indicated, L. thunbergianus (Kaulfuss) Ching, which was not included in J. Smith’s original treatment of Drynaria sect. Lepisorus.

Lepisorus is complex both cytologically and morphologically with many taxa still inadequately known. Because of this, we have treated species conservatively. Though relatively recently described, the genus has become well established, especially as molecular studies have shown that the similarity to the genus Pleopeltis Humboldt & Bonpland ex Willdenow is probably the result of morphological convergence and that the two genera belong to phylogenetically distinct lines. These same studies (e.g., Li Wang et al., Molec. Phylogen. Evol. 54: 211-225. 2010) demonstrated that two older, but much smaller, genera, Belvisia and Drymotaenium, nest within Lepisorus. Lepisorus has been formally proposed for conservation against these competing earlier names.

About 80 species; mainly in E Asia, a few in Africa, one species in Hawaii; 49 species (23 endemic) in China.

(Authors: Qi Xinping (齐新萍), Zhang Xianchun (张宪春), Lin Youxing (林尤兴); Michael G. Gilbert, Peter H. Hovenkamp)