Polystichum incongruum J.P.Roux

Plants terrestrial. Rhizome decumbent, stout, to 16 mm in diameter, sparsely branched, set with roots, crowded stipe bases, and castaneous to ferrugineous, chartaceous paleae. Fronds crowded, to 8 per plant, suberect to arching, to 1.8 m long: stipe proximally castaneous, stramineous for most of its length, adaxially sulcate, to 930 mm long x 7 mm in diameter, moderately to densely paleated; paleae at stipe base of two types, the larger broadly attached, ferrugineous to stramineous, membranous, narrowly to broadly ovate-acuminate, rarely with unicellular clavate cells on the paleae surface, cordate to cordate-imbricate, the margins with short close-set outgrowths, the apex often flagelliform, terminating in an acicular cell or an oblong thin-walled cell, to 20 x 6 mm, the smaller sessile to short-stalked, stramineous, membranous, narrowly ovate-acuminate to narrowly triangular, truncate to cordate-imbricate, with short and/or long, straight or curved, somewhat lacerate outgrowths proximally, the apex flagelliform, entire and twisted, mostly terminating in an acicular cell but often also in a thin-walled cell: lamina 2-pinnate to 3-pinnate, with up to 27 free pinna pairs, ovate to broadly ovate, to 870 mm long, the pinnae more widely spaced proximally, the distal pinnae often imbricate, the proximal pinnae not to strongly reduced, not or slightly deflexed: rachis stramineous, adaxially sulcate, moderately to densely paleated; paleae sessile to short-stalked, ferrugineous to stramineous, membranous, narrowly ovate-acuminate to narrowly triangular-acuminate, truncate, cordate or cordate-imbricate, the margins proximally with short and/or long, curved, often branched outgrowths reduced in size and number towards the apex, the apex often flagelliform, twisted, terminating in an acicular cell or an oblong thin-walled cell, to 12 x 3 mm: pinnae 1-pinnate to 2-pinnate, with up to 21 free pinnule pairs, narrowly oblong-attenuate to narrowly ovate-attenuate, the middle pinnae to 265 mm long, to 95 mm wide: pinna-rachis stramineous, adaxially sulcate, moderately to densely paleated; paleae sessile to short-stalked, ferrugineous to stramineous, membranous, narrowly ovate-acuminate, narrowly triangular-acuminate to subulate, cordate to cordate-imbricate, the proximal margins with short and/or long, often branched outgrowths reduced in size and number towards the apex, the apex often flagelliform, twisted, largely terminating in an acicular cell but often also in an oblong thin-walled cell, to 7 x 2 mm: pinnules opposite to alternate, closely to widely spaced, often slightly imbricate, firmly herbaceous to coriaceous, dark green adaxially, slightly paler abaxially, inaequilateral, ovate to narrowly trullate, often somewhat falcate, basiscopically cuneate, acroscopically cuneate to truncate and auriculate, the larger pinnules commonly deeply incised to form free or nearly free, narrowly ovate, narrowly elliptic to narrowly obovate ultimate segments, the margins serrate to doubly serrate, rarely aristate, the proximal acroscopic pinnule to 60 mm long, to 13 mm wide, often overlapping the pinna-rachis above; adaxially sparsely set with stramineous, membranous, twisted paleae chiefly along the costa, these filiform, narrowly linear to narrowly linear-hastate, simple or with few short marginal outgrowths proximally, the apex usually terminating in an acicular cell but often also in an oblong thin-walled cell, to 4.5 mm long, abaxially moderately paleated; paleae stramineous, membranous, subulate to narrowly triangular, twisted, short-stalked, truncate to cordate, proximally with short and/or long, often branched, somewhat lacerate marginal outgrowths, the apex usually terminating in an acicular cell, up to 3.5 mm long. Venation adaxially obscure, raised abaxially. Sori circular, up to 1.5 mm in diameter, terminal or near terminal on abbreviated vein branches, essentially uniseriate, discrete: sporangium with 11-(13)-21 indurated annulus cells; stalk glandular or eglandular: indusium stramineous or stramineous and black-centred, persistent, circular, simple or with central processes, the margins entire, minutely undulate to erase, often bearing clavate unicellular glands, the maximum radius 0.22-(0.46)-0.82 mm. Spores stramineous, the perispore folded to form narrow and broad reticulate ridges, the ridges crested, the crests and areas between minutely echinulate, porate, the exospore 30-(43.84)-72 x 22-(33.22)-52 µm.