Asplenium boltonii Hook. ex Schelpe

Plants terrestrial, epilithic or epiphytic. Rhizome short, erect to suberect, to 20 mm long, to 5 mm in diameter, set with roots, crowded persistent stipe bases and scales, scales chartaceous to thinly chartaceous, ferrugineous to castaneous, clathrate, adnate, lanceolate, cordate, margins regularly set with short and long filiform outgrowths terminating in an enlarged obovate thin-walled cell, apex terminates in an enlarged thin-walled cell, to 16 mm long, to 3 mm wide. Fronds crowded, caespitose, arching, to 820 mm long; stipe atrocastaneous, matt, adaxially sulcate, to 170 mm long, to 3 mm in diameter, initially densely scaled, scales chartaceous, castaneous, sessile, linear to filiform, cordate to cordate-imbricate, larger scale margins regularly set with short and long filiform outgrowths terminating in an enlarged thin-walled cell, filiform scales with gland-like cells and short outgrowths terminating in an enlarged thin-walled cell at the base, apex terminates in an enlarged thin-walled cell, to 10 mm long, to 1 mm wide; lamina anadromous, 1-pinnate, lanceolate, to 650 mm long, to 190 mm wide, with up to 21 petiolated pinna pairs, with a proliferous bud adaxially on the rachis near the apex; rachis firm, atrocastaneous, adaxially sulcate, moderately set with filiform scales similar to those on the stipe; pinnae petiolate, petiole to 2 mm long, opposite to alternate, basally more widely spaced than apically, the 2-3 basal pairs generally gradually reduced, firmly herbaceous, inequilaterally lanceolate, often somewhat falcate, acroscopically truncate to broadly cuneate, basiscopically narrowly to broadly cuneate, dentate, usually with alternating shallower and deeper incisions, to 120 mm long, to 20 mm wide, adaxially sparsely set with filiform scales along the costa similar to those on the stipe, abaxially sparsely set with filiform scales along the costa and veins similar to those on the stipe, to 2.5 mm long; costa adaxially raised, convex. Venation anadromous, evident, pinnately branched, branches forked, ending in the teeth near the margin. Sori linear, inframedial, at or above a vein fork, to 8 mm long; indusium chartaceous, stramineous, linear, entire, to 8 mm long, 1.4 mm wide; sporangium long-stalked, uniseriate, 3-seriate below the capsule, capsule globose in lateral view, annulus (17-)19(-20)-celled, epistomium 2-celled, hypostomium 4-celled. Spores 64 per sporangium, brown, elliptic, monolete, perispore forms broad reticulate wings, exospore (40-)46.3(-50) x (30-)31.8(-34) µm.