Compilation
Nephrolepis undulata

Mostly terrestrial but also on rocks, on trees and sometimes in axils of palmleaves. Rootstock usually annual, erect, weak, producing a few short wiry stolons bearing round to ellipsoid tubers (1–)2–3 cm long. Fronds erect or drooping, solitary or 2–3(–5), narrowly oblong-elliptic or linear-lanceolate, (15–)35–100(–150) cm long, (2.5–)4–8 cm wide, more or less gradually tapering to base and apex from the middle; stipe (3–)5–25 cm long; rhachis glabrous, glabrescent or with few hair-like scales; fertile pinnae approximate to imbricate or remote, narrowly elongate-triangular to ovate-oblong from the much enlarged or ± not enlarged base, sometimes ± falcate, 0.8–6 cm long, 0.4–1.5 cm wide, abruptly tapering uniformly upwards to acute or subobtuse apex, sinuate to coarsely crenate or minutely crenate-serrate at the margins; base truncate or somewhat asymmetric with a small or very wide rounded auricle on the acroscopic side, scarcely overlapping or much overlapping the rhachis and concealing or not concealing the rhachis beneath, with a smaller rounded auricle on the basiscopic side; sterile pinnae very numerous or fewer, remote or usually approximate, somewhat different from fertile, oblong-triangular, obtuse. Sori semilunate, set in a line about halfway between the costa and the margin on both sides, up to 1.5 mm in diameter; indusia cream, reniform, the free edge opening towards apex of pinna (or sometimes extreme basal ones towards the margin). Fig. 1/1–2.