Megalastrum lanuginosum (Kaulf.) Holttum

Plants terrestrial. Rhizome erect, to 450 mm long, to 30 mm in diameter, set with roots, crowded persistent stipe bases and scales, scales chartaceous, castaneous, sessile, linear to filiform, denticulate, often with a few filiform outgrowths at the base, apex terminates in a small thin-walled cell, to 13 mm long, to 0.5 mm wide. Fronds crowded, caespitose, arching, to 1.9 m long; stipe firm, basally castaneous to ferrugineous, brown distally, to 780 mm long, to 11 mm in diameter, set with scales and hairs, scales sparsely set, castaneous to ferrugineous, chartaceous, sessile, linear to filiform, denticulate, apex terminates in a small thin-walled cell, to 3.5 mm long, to 0.4 mm wide, hairs pluricellular, acicular or filiform, acicular hairs terminating in a gland-like cell, to 560 µm long, filiform hairs to 0.3 mm long; lamina anadromous proximally, catadromous distally, elliptic, to 4-pinnate, to 1.2 m long, to 1 m wide, with up to 15 petiolated pinna pairs, distal pinnae adnate, basiscopically decurrent along the rachis; rachis stramineous, adaxially sulcate, sulcus not open to that of the lower order axes, closely set with scales and hairs similar to those on the stipe; pinnae petiolate, petiole to 22 mm long, alternate, overlapping, basal pinna pair to 2-pinnate, basiscopically developed, inequilaterally ovate-deltate, to 550 mm long, to 430 mm wide, oblong-cuneate higher up, with up to 14 petiolated pinnule pairs, distal pinnules adnate, basiscopically decurrent along the pinna-rachis; pinna-rachis adaxially shallowly sulcate, sparsely set with appressed scales similar to, but smaller than, those on the rachis, closely set with hairs similar to those on the rachis; pinnules petiolate, petiole to 6 mm long, alternate, spaced or slightly overlapping, to 1-pinnate-pinnatifid, acroscopic pinnules lanceolate to oblong-cuneate, to 110 mm long, to 34 mm wide, proximal basiscopic pinnule basiscopically developed, inequilaterally ovate, to 350 mm long, to 130 mm wide; pinnule-rachis adaxially sulcate, set with scales and hairs similar to those on the pinna-rachis; segments petiolate, petiole to 2 mm long, alternate, spaced, pinnatifid, oblong-cuneate, to 82 mm long, to 19 mm wide, with up to 14 ultimate segment pairs; costa adaxially closely set with stramineous, pluricellular, acicular hairs, to 0.8 mm long, and pluricellular, filiform hairs, to 0.3 mm long, abaxially set with scales and hairs, scales chartaceous, ferrugineous, sessile, subulate, bullate, denticulate, often with short filiform outgrowths at the base, to 3 mm long, to 0.8 mm wide, and hairs similar to, but slightly longer than, those on the adaxial surface; ultimate segments sessile, herbaceous, opposite to alternate, adnate and increasingly more basiscopically decurrent along the costa towards the apex, to 11 mm long, to 4 mm wide, lobed, denticulate, costule and lamina regularly set with stramineous, pluricellular, acicular hairs to 1 mm long along the veins, and unicellular gland-like hairs between the veins, abaxially more closely set with hairs similar to those on the adaxial surface, acicular hairs also occur between the veins and along the margin, to 1.2 mm long. Venation catadromous, evident, pinnately branched, vein branches terminate near the margin in the sinus between the teeth. Sori circular, to 1 mm in diameter, terminally on the anadromous vein branches, or on unabbreviated vein branches; sporangium long-stalked, simple, 3-seriate below the capsule, capsule globose in lateral view, with 13(-15) indurated annulus cells, epistomium 3(-4)-celled, hypostomium 4-celled; indusium chartaceous, ferrugineous, reniform, to 0.6 mm in diameter, bearing unicellular glands, cylindrical and acicular hairs along the margin and surface. Spores 64 per sporangium, dark brown, ellipsoidal, monolete, echinate, (28-)32.2(-36) x (22-)24.75(-26) µm.