Hymenophyllum applanatum (A.M.Gray & R.G.Williams) Ebihara & K.Iwats.

Rhizome long-creeping, branched, finely longitudinally ribbed, glossy brown, with stalked stellate ferruginous hairs. Stipe unwinged, filiform, 4–45 mm long, smooth, brown; ribs and hairs similar to those of rhizome; hairs tufted near the base, scattered above. Lamina decompound, 1–8 cm long, 0.5–3.5 cm wide, lacking conventional blades, grey becoming rusty brown. Frond axes narrowly winged; conventional epidermis lacking, replaced by a very absorbent 'felt', comprising a single layer of parenchyma cells prolonged into sausage-shaped whitish papillae, intermixed with 5–7-armed ferruginous stellate hairs. Primary pinnae 5–15 mm long, 5–10 mm wide; lower parts ovate-rhomboidal; upper ones ± flabellate. Ultimate segments distinctly winged, flattened, not rigid, linear-oblong; apices acute. Sori terminal on the segments; involucre ovoid-cupular, scarcely bilabiate, c. 0.7–1 mm long, c. 1 mm wide, densely clothed with papillae and matted stellate hairs, with entire or crenulate rims; receptacle rarely included, mostly exserted up to 1.5 mm beyond the rim, terete, setaceous.

Occurs in high rainfall areas in rock fissures often well above the tree line, or epiphytic on Athrotaxis species (e.g. A. selaginoides ) or rarely on the bark of Banksia marginata.