Perennial herb with deciduous aerial parts. Rhizome fusiform to thickly linear, 7–22 mm long, 1.5–5 mm wide; roots fleshy, horizontal, proliferous. Leaves usually single; stipe (12–)27–69(–100) mm long, 25–40% of its length subterranean, stipe:lamina length ratio 0.5–1.9:1, stipe bases not persistent; lamina dull green, elliptic, narrowly elliptic or lanceolate, fertile lamina somewhat folded along the midline, (22–)28–50(–60) mm long, (6–)8–13(–15) mm wide, length:width ratio 2.5–5.7:1, apex acute, often apiculate, base narrowly cuneate, margins flat; venation linear medially, elongate laterally, with secondary veins and included veinlets confined to the lateral areoles; epidermal cells linear with wavy walls medially, to elongate with sinuous anticlinal walls laterally; stomata partially aligned. Fertile spike (77–)95–115(–140) mm long, fertile spike:lamina length ratio 2–4.1:1, with (9–)12–21(–29) pairs of sporangia. Spores 30–40 µm in equatorial diameter, trilete, the muri often so broad that the lumina are reduced to conical pits, superficially smooth but always minutely undulate (sensuMurley in Stearn 1978).
