Asplenium inaequilaterale Willd.

Plants epilithic. Rhizome short, erect to suberect, to 20 mm long, to 4 mm in diameter, set with roots, crowded persistent stipe bases and scales, scales crustaceous, atrocastaneous to black, clathrate, sessile, subulate to lanceolate, cordate to cordate-imbricate, entire or with scattered, pluricellular recurved outgrowths along the margin, apex terminates in a thin-walled cell, to 5 mm long, to 0.7 mm wide. Fronds crowded, caespitose, erect, to 430 mm long; stipe firm, castaneous, matt, terete, to 210 mm long, to 1.6 mm in diameter, narrowly green-winged to the base, base sparsely set with scales similar to those on the rhizome, higher up with filiform clathrate scales terminating in an elliptic thin-walled cell, to 1 mm long, and 3 or 4-celled hairs terminating in an enlarged obovate thin-walled cell, to 0.3 mm long; lamina 1-pinnate, narrowly elliptic, to 230 mm long, to 68 mm wide, with up to 17 petiolated pinna pairs; rachis firm, castaneous to greenish higher up, shallowly sulcate adaxially, narrowly green-winged, set with filiform scales and hairs similar to those on the stipe, glabrous later; pinnae basal pinnae petiolate, petiole to 1.5 mm long, sessile towards the apex, herbaceous, dark to mid-green, opposite to alternate, basally more widely spaced than apically, often slightly overlapping, basal 2-4 pairs often gradually reduced, inequilaterally lanceolate to trapezoid, acroscopically truncate, basiscopically excavate, usually alternately shallowly and deeply dentate, to 38 mm long, to 10 mm wide, glabrous adaxially and abaxially; costa adaxially raised, convex. Venation anadromous, evident, pinnately branched, branches forked, ending in the teeth near the margin. Sori linear, usually at or above a vein fork, to 4 mm long; indusium chartaceous, stramineous, transversely narrowly elliptic, entire, to 4 mm long, to 1.2 mm wide; sporangium long-stalked, uniseriate, 3-seriate below the capsule, capsule globose in lateral view, annulus with 19(-22) indurated annulus cells, epistomium 2(-3)-celled, hypostomium 4(-5)-celled. Spores 64 per sporangium, brown, elliptic, monolete, perispore forms broad reticulate wings, erose, the areas between the wings irregularly echinulate, exospore (30-)32.2(-36) x (20-)22.3(-24) µm.