Nephrolepis undulata (Afzel. ex Sw.) J. Sm.

undulata: wavy, unclear reference, possibly describing the pinna margins.

Rhizome short, erect, with long stolons, in places producing elliptical tubers, up to 25 mm long, from which new plants arise. Fronds few, tufted, erect, herbaceous. Stipe up to 16 cm long, brown, with sparse narrowly lanceolate, entire, brown scales up to 4 mm long, glabrous with age. Lamina up to 90 × 11 cm, narrowly elliptic to lanceolate in outline, pinnate, lower pinnae gradually reduced. Pinnae sessile, articulated, closely spaced or overlapping, narrowly oblong in outline, base cordate and auricled or lobed on the acroscopic side, overlapping on to the rhachis, apex rounded to pointed, both surfaces glabrous, margins entire or crenate, veins free, ending in an inconspicuous submarginal hydathode. Rhachis stramineous to pale brown, glabrous to subglabrous. Sori c. 1.5 mm wide, semi-lunulate, set in a submarginal line along both sides of the pinnae; indusia facing the margin, semi-lunulate, membranous, entire.

Worldwide, widespread in Africa and tropical Central and South America.