Adiantum raddianum C.Presl

Plants terrestrial or epilithic. Rhizome short-creeping, irregularly branched, to 50 mm long, to 2 mm in diameter, set with roots, closely spaced persistent stipe bases and scales, scales firmly chartaceous, castaneus, adnate, subulate to narrowly triangular, entire to denticulate, apex terminates in a short subulate cell, to 1 mm long, to 0.3 mm wide. Fronds to 4 mm apart, erect to arching, to 640 mm long; stipe firm, atrocastaneus, nitid, terete, to 350 mm long, to 1.2 mm in diameter, basally set with scales similar to those on rhizome, to 2 mm long, to 0.5 mm wide, glabrous apically; lamina anadromous, ovate to broadly ovate, to 3-pinnate, to 300 mm long, to 220 mm wide, with up to 12 pinna pairs; rachis and lower order axes atrocastaneus, nitid, terete, glabrous; pinnae petiolate, petiole to 25 mm long, alternate, basal pinnae largest, more widely spaced than apically, usually overlapping, to 2-pinnate, ovate, to 130 mm long, to 90 mm wide, with up to 8 pinnule pairs; pinnules petiolate, petiole to 8 mm long, alternate, usually overlapping, ovate, to 55 mm long, to 36 mm wide, with up to 5 segment pairs; ultimate segments petiolate, petioles to 2 mm long, alternate, thinly herbaceous, flabellate, narrowly to broadly cuneate, variously lobed, lobes dentate, to 10 mm long, to 10 mm wide, glabrous adaxially and abaxially. Venation evident, flabellately forked, ending in margin in sinus between teeth. Sori borne along outer margin of ultimate segment lobes, on soral flaps which veins enter, soral flaps membranous, subcircular to reniform, to 2 mm in diameter; sporangia confined to veins, sessile, capsule circular to obovate in lateral view, with 19(-21) indurated annulus cells, epistomium (4-)5-celled, hypostomium (4-)5(-6)-celled, stomium with 3 or 4 narrow cells of which walls are conspicuously thickened; Spores brown, tetrahedral-globose, trilete, rugulose, exospore (40-)44(-48) µm in equatorial diameter.