Onychium Kaulf.

Plants terrestrial or less commonly on rocks. Rhizomes long creeping or rarely short and decumbent, siphonostelic, scaly, scales concolorous, light brown to reddish brown, opaque to somewhat translucent, non-clathrate, linear-lanceolate to ovate-lanceolate, margins entire. Fronds monomorphic to somewhat dimorphic, widely or closely spaced. Stipe straw-colored above a usually darker proximal portion, occasionally uniformly straw-colored or reddish brown to dark brown (especially abaxially), glabrous above scaly base, with (1 or)2 vascular bundles at base, adaxially grooved. Lamina ovate-deltoid or ovate-lanceolate, less often elongate lanceolate, herbaceous or papery, finely 2-5-pinnate-pinnatifid, rarely 2-pinnate, glabrous or nearly so or fertile segments yellow-farinose abaxially; rachis and costae usually grooved adaxially. Pinnae alternate. Ultimate segments or lobes narrow and small, lanceolate to oblong-lanceolate or narrowly oblong, base cuneate and often decurrent, apex acute or acuminate. Veins simple or pinnately branched, free, slightly thickened, sometimes raised abaxially, in fertile segments veinlets connected by an inframarginal commisural vein. Sori borne along commisural veins, linear. False indusia usually well developed, membranous, continuous but interrupted at segment apex and base, reaching to midvein or nearly so (narrow in Onychium tenuifrons), margins entire, slightly undulate, or less commonly erose. Spores trilete, globose-tetrahedral, perispore coarsely tuberculate-reticulate on distal face, proximal face tuberculate and with prominent, coarse ridges parallel to equatorial flange. x = 29.