Pteris friesii Hieron.in Fries

Plants terrestrial. Rhizome erect to suberect, simple, to 90 mm long, 10 mm in diameter, set with roots, stipe bases and scales, scales crustaceous, bicolorous, centrally with a broad atrocastaneus region, sessile, narrowly lanceolate, margins hyaline, closely set with pluricellular, uniseriate hairs terminating in a pyriform apical cell, apex terminates in an oblong or pyriform cell, to 5 mm long, to 0.7 mm wide. Fronds caespitose, arching, to 1.9 m long, to 7 per plant; stipe firm, proximally castaneus, stramineous to greenish distally, adaxially sulcate, to 1.2 m long, to 6 mm in diameter, proximally sparsely set with scales similar to those on rhizome, glabrous distally; lamina anadromous, ovate, to 2-pinnate, to 800 mm long, to 520 mm wide, with up to 14 free pinna pairs; rachis brown to stramineous, adaxially sulcate, glabrous; pinnae petiolate, petiole to 10 mm long, opposite to alternate, basal pinna pair largest, spaced, with a single pinnule basiscopically, strongly inequilaterally triangular, to 260 mm long, to 170 mm wide, distal pinnae linear-acuminate to narrowly lanceolate, pectinate; pinna-rachis adaxially shallowly sulcate, with prickles where costae branch from higher order axes, pronounced abaxially; pinnules sessile or petiolate, petiole to 2 mm long, narrowly lanceolate, pectinate, to 170 mm long, to 45 mm wide; lobes firmly herbaceous, linear-acuminate to linear-obtuse, entire, to 29 mm long, to 6 mm wide, adaxially sparsely set with 3-5-celled hairs mainly along costule and veins, to 0.3 mm long, abaxially sparsely set with 3-5-celled hairs, to 0.2 mm long; costa adaxially shallowly sulcate, without prickles, or shortly dentate. Venation evident, forked once, ending in margin, free in sterile fronds. Sori linear, continuous along a marginal vascular commissure, extending from near lobe base close to apex; receptacle paraphysate, paraphyses simple, pluricellular, apical cell slightly enlarged, to 0.6 mm long; sporangium long-stalked, simple, 3-seriate below capsule, capsule elliptic to obovate in lateral view, annulus with (16-)17(-19) indurated annulus cells, epistomium 4(-6)-celled, hypostomium 4(-5)-celled, stomium 2-celled, walls conspicuously thickened; indusium firm, brown, linear, repand, to 0.4 mm wide. Spores 32 per sporangium, brown, tetrahedral, trilete, with an equatorial flange, rugate, (56-)61.17(-66) µm in equatorial diameter.