Plants terrestrial, small to medium-sized, 10-150(-200) cm tall, without scales. Rhizomes dictyostelic, erect, suberect, or shortly decumbent, stout, thickened; stipe bases persistent. Roots blackish, wiry, regularly arranged on stem, one beside each stipe base, sparsely branched. Fronds dimorphic, bearing minute, uniseriate, multicellular, gland-tipped, mucilage-secreting trichomes. Stipes orbicular, ovate, triangular, or tetragonal in cross section, bases swollen; vascular bundle 1 per stipe, expanded or divided into 3 meristeles in enlarged base; rachises winged or not, abaxially semiterete, flat, or carinate, adaxially sulcate. Aerophores variously present on stipes and rachises, cushionlike or elongate and hornlike with blunt apex. Sterile fronds herbaceous, firmly so, or subleathery; lamina 1-pinnate, pinnatifid, or pinnatilobed, apices coadunate, pinnalike, pinnatilobed, or confluent; pinnae sessile, shortly stalked, or adnate to rachises, falcate to linear-lanceolate, widest near base or below middle, glabrous or abaxially sparsely glandular pubescent, margin entire to serrulate, apex minutely serrulate to dentate; veins simple or paired at base, mostly 1-or 2-forked, reaching pinna margins, distinct on both surfaces. Fertile fronds erect at middle of plant, with proportionally longer stipes and shorter lamina; lamina pinnate or deeply pinnatifid; pinnae sessile, shortly stalked, or adnate to rachises; apical pinna usually pinnatifid or pinnalike, margin entire, subentire, or erose-toothed, glabrous or with few short glandular hairs, scarious; tissue above veinlets hygroscopic and reversible, functioning as indusium (false indusium), scarious margins covering sori in juvenile stage, recurved at maturity; veins free, 1-or 2-forked, solitary or paired at base. Sori borne on swollen vein tips, extending slightly, confluent, acrostichoid, almost wholly covering abaxial surface of pinnae when ripe. Paraphyses numerous, mixed with sporangia, uniseriate, orange to dark brown, multicellular, glandlike, slightly longer than sporangia, apically subcapitate. Sporangia with a complete oblique annulus, not interrupted by stalk, laterally dehiscent. Spores 64 per sporangium, tetrahedral; aperture trilete; arms of aperture ca. 3/4 radius; surface ornamentation irregular, coarse, tuberculate with coalescent papillae and rodlets. x = 65 (sexual).
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