Parablechnum novae-zelandiae

Detailed description

Rhizome short-creeping, very robust in larger specimens, occasionally suberect or erect; scales to 16 × 3 mm, linear or lanceolate, acuminate, light reddish brown, sometimes dark at base, more or less entire. Fronds dimorphic, erect or pendulous, 0.09–0.3 m (in dry exposed places and in swamps) –3.5 m long (on stream banks) × 35–500 mm wide, widest mid frond; sterile and fertile fronds usually similar length. Stipes 0.08–0.75 m (stipes of fertile fronds often shorter than stipes of sterile fronds), stout, to c. 10 mm diameter, pale brown or pinkish brown, darkening at base, scaly, especially at the base; scales 2–20 × 1–3 mm wide, but mostly small and appressed, ovate, reddish brown, concolorous or “black-spot”, entire or branched at their bases. Lamina ovate or lanceolate, bright mid green at maturity, 1-pinnate, 5–50 pairs of pinnae. Rachis and costae pale pinkish brown, with sparse to moderately dense scales and irregular fine short tangled hairs; scales 3.0–15.0 × 1.0–1.5 mm, variable in shape from linear to ovate or sometimes stellate, pale brown, reddish brown, “black spot” (especially conspicuous for costal scales), or sometimes entirely concolorous (juveniles and plants growing in swamps, and most plants on the Kermadec islands), entire or toothed. Sterile pinnae 20–350 × 6–30 mm, oblong-lanceolate to lanceolate, apices acute, acuminate, or attenuate, or, in juveniles and smaller plants growing in swamps, obtuse; cuneate, truncate, or rounded-cordate at rachis; sub-petiolate at base of lamina, adnate and decurrent at apex; mostly coriaceous but almost membranous in juveniles and plants growing in swamps; margins minutely toothed, more so near apices; veins simple or once-furcate; small-branched or stellate scales often extending on to lower surface of pinnae; basal pinnae rounder and nearly always significantly shorter than middle pinnae, with 2–11 pairs of sterile auricles (small plants from swamps, very harsh conditions, and from low light conditions may lack auricles); terminal pinna longer than subterminal pinnae. Fertile pinnae 20.0–250 × 1.5–6.0 mm, narrow, linear, sessile at base of lamina, becoming basiscopically adnate at apex; basal pinnae often with sterile auriculate segments at their bases, the lowermost sometimes completely sterile and auriculate; sori covering under surface except for auriculate zone and the short sterile apical region; indusium brown, laciniate. Spores 40–60 × 32–43 µm.