Parablechnum procerum

Detailed description

Rhizome short-creeping; scales to 16 × 2 mm wide, lanceolate, acute or acuminate, brown some bicolorous, entire. Fronds dimorphic, erect, 0.08–1.0 m long, 45–220 mm wide, widest mid frond; fertile fronds longer and more erect than sterile fronds. Stipes 20–600 mm (stipes up to 180 mm for plants growing in tussock communities, 150–250 for plants growing in open, shaded forest, and up to 0.6 m where plants are competing with a dense ground layer in the forest); stipes of sterile fronds shorter than stipes of fertile fronds, 1–4 mm diameter, stramineous to dark brown, becoming darker reddish brown towards the base; stipes scaly when young, often glabrous at maturity; scales 2–10 mm long, 0.5–1.5 mm wide, mostly lanceolate, brown, reddish brown, or somewhat bicolorous with paler margins, entire. Lamina ovate or lanceolate, dark olive green at maturity, 1-pinnate, 2–15 pairs of pinnae (plants suboptimal sites occasionally have as few as 1 terminal and 2 lateral, membranous pinnae), fertile laminae with more pinnae than sterile laminae. Rachis and costae dark, reddish, or pale brown (usually pale for specimens from open tussock communities), often blotchy; with sparse to numerous scales (fertile lamina with a more scaly rachis) and some small irregular hairs; scales variable in size, shape, and colour, 3.0–10.0 × 0.5–1.0 mm, linear to lanceolate, attenuate, more or less entire; conspicuous abaxial costal scales 2.0–3.5 mm long, c. 1 mm wide, of small narrow linear cells, lanceolate, attenuate, shiny dark reddish brown, concolorous or sometimes slightly bicolorous with paler margins (but lacking a “black-spot”), more or less entire. Sterile pinnae 25–150 × 10–35 mm, oblong-lanceolate, apices obtuse to acute, rounded or truncate at rachis; shortly petiolate at base of lamina, basiscopically adnate towards apex; coriaceous in robust specimens to almost membranous in small plants; margins toothed and sometimes crenate; veins simple or once-furcate; small toothed scales often extending on to lower surface of pinnae; basal pinnae as long or slightly 10–35 mm, oblong-lanceolate, apices obtuse to acute, rounded or truncate at rachis; shortly petiolate at base of lamina, basiscopically adnate towards apex; coriaceous in robust specimens to almost membranous in small plants; margins toothed and sometimes crenate; veins simple or once-furcate; small toothed scales often extending on to lower surface of pinnae; basal pinnae as long or slightly shorter than middle pinnae, rarely less than half their length, more obtuse, often reflexed, auricles and auriculate pinnae bases absent; terminal pinna usually longer and acutely pointed. Fertile pinnae 20–75 × 2.0–4.5 mm, linear, shortly petiolate at base of lamina, becoming basiscopically adnate towards apex; basal pinnae usually not reduced; sori covering under surface except at apices; indusium brown, laciniate or entire. Spores 56–70 × 39–52 µm.