Parapolystichum kermadecense

Detailed description

Terrestrial fern. Rhizomes erect or short creeping with fronds clustered at apex. Rhizome scales similar to, but narrower than, those on stipe, non-clathrate, margins entire to abundantly ciliate, cilia apices sometimes globular. Stipes stramineous to castaneous, darker towards the rhizome, 100–500 × 1–4 mm diameter, lacking hairs or with scattered hairs 250–700 mm long, scaly proximally. Stipe scales brown to dark-brown, the more distal clathrate, narrowly-triangular or narrowly ovate, 5.0–12.0 × 0.8–2.1 mm, margins entire to repand (or ciliate). Laminae green, paler abaxially, 3-pinnate to 3-pinnate-pinnatifid, with 8–13 pairs of primary pinnae of which 0–1–(2) catadromous, angular-ovate to pentagonal, 145–450 × 100–330 mm wide, apex acuminate. Rachises 140–420 mm long, adaxial sulcus densely set with erect ctenitoid hairs, the hairs 80–180 mm long, reddish-clear to red or orange; abaxially glabrous or proximally nearly so, or with scattered hairs, often clustered at junctions with primary pinnae and sometimes many distally, the hairs clear with red transverse cell walls, mostly 170–350 mm long, occasionally or commonly interspersed with longer hairs up to 700 mm. Proximal pair of primary pinnae 75–250 × 50–210 mm, with proximal basiscopic secondary pinna enlarged, 35–150 × 11–45 mm. Primary pinnae in apical third of lamina pinnate-pinnatifid, very occasionally 2-pinnate with ½–1 pair of secondary pinnae. Ultimate segments sparsely serrate-crenate, the apex obtuse to acute but with several teeth. Costa of primary pinnae adaxially with hairs similar to those of adaxial rachis, but paler and up to 270 mm long, thinning distally so that minor veins and lamina usually glabrous or nearly so; abaxially glabrous or densely hairy, especially proximally, the hairs usually inconspicuous, clear or reddish clear, predominantly ctenitoid, 170–270 mm long, thinning distally so that minor veins and lamina almost glabrous, sinuses between secondary pinnae with no or few hairs. Glands inconspicuous, absent or few on abaxial rachis, few to many on abaxial lamina, yellow to orange, often pale, 70–140 mm. Sori circular, 0.9–2.1 mm in diameter. Indusia persistent, round to ovate, cordate with a narrow to broad sinus, brown to reddish-brown, 0.7–1.3 mm diameter, only partially covering mature sori, glands absent or present on the dorsal surface or margin. Spores monolete 29–34 × 22–27 µm.