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.
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Epiphytic, sometimes terrestrial, medium-sized ferns. Rhizome short-to long-creep-ing, approximately terete, covered with scales, dorsally with 2 rows of fronds, sparsely to densely set with roots, dictyostelic, with or without scattered sclerenchyma strands. Rhizome scales basifixed, pseudopeltate, ovate to linear-lanceolate, fully clath-rate or with a membranaceous margin, reddish to brown, entire to dentate, sometimes with a tuft of hairs near the point of attachment. Fronds simple, entire, stipitate. Lamina narrowly ovate to linear, the base narrowly cuneate to truncate, the apex round-ed, acute or acuminate, olivaceous to brown when dry, dull, pergamentaceous or chartaceous, glabrous or thinly covered with scattered clathrate scales. Venation: the midrib distinct, main veins distinct halfway to the margin or indistinct, anastomos-ing and forming irregular areoles with many free veinlets, free veinlets excurrent and recurrent, immersed. Sori in a single row between midrib and margin, round or sometimes elongated, 2-10 by 2-6 mm, densely covered with more or less persis-tent clathrate scales when young. Sporangia stalked, with 13-16 indurated annulus cells, mixed with peltate or basally attached paraphyses. Spores monolete, rugulate.
Fronds larger, not dimorphous
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