Epiphytic, less often on wet rocks, rarely terrestrial; rhizome erect or creeping, 3–7 mm diameter, and with mid-brown clathrate lanceolate entire sharply acute rhizome scales 1–3x0.2 mm. Fronds tufted or slightly spaced, arching or hanging, firmly herbaceous, 15–65 cm long, not proliferous; stipe matt brown or green above and black beneath, often darker towards the base, 6–20 cm long, with scattered scales similar to those on the rhizome, otherwise glabrous at maturity; lamina narrowly to very narrowly oblong, 13–45x4–9(–16) cm, 2-pinnatisect to weakly 3-pinnatifid, lowest pinnae not reduced, apical pinnae decrescent, apical pinna linear and much-lobed; pinnae in 15–21 pairs, subopposite to alternate, unequally rhombic-attenuate, 2–7(–12)x0.5–2.5(–3) cm, petiolate, very unequally cuneate at the base, the basal acroscopic lobe often oblong and larger than the rest, deeply pinnatifid into 4–9 pairs of narrowly ob-cuneiform to linear truncate-denticulate or truncate-serrate lobes, the lobes of the pinnae ± equal except for the basal acroscopic lobe; glabrous on both surfaces; veins flabellate; rachis matt brown, glabrous at maturity. Sori 1–3 per lobe but also characteristically on the wing along the costa, linear, 1–7 mm long; indusium linear, membranous, entire, 0.3–0.5 mm wide. Fig. 9: 1–2, p. 54.