Tectaria siifolia (Willd.) Copel.

Caudex short-creeping; fronds dimorphous, sterile ones with shorter stipe and broader pinnae than fertile, pinnae to 4 pairs; fronds of young plants ovate-acute with strongly cordate base. Sterile fronds: stipe to 30 cm long, glabrous, basal scales to 10 mm long, dark with thinner pale margins; apical lamina often trilobed, the middle lobe sometimes with sinuous margins; buds present at bases of pinnae on old fronds; basal pinnae to 20 cm long, to 7 cm wide above the basal lobe, abruptly short-acuminate; middle pinnae broader on basiscopic than on acroscopic side of the costa; main veins to 10 mm apart along costae; upper surface of costae glabrous except near their base in Sumatra, closely short-hairy in Celebes and Philippines, lower surfaces glabrous. Fertile fronds: stipe to 50 cm long; middle pinnae to c. 12 × 4 cm with main veins to 6 mm apart along costae, areoles between main veins fewer than in sterile pinnae and in smaller pinnae lacking included veinlets; sori on the outer veins of areoles, in a row on each side of main veins, usually rather large, those near the costae elongate and often coalescing to form lines parallel to the costa; indusia thin, soon caducous.

Terrestrial in rainforest beside watercourses or springs. On Christmas Island collected in an area extensively mined, and may still exist on the remaining rock outcrops or gullies (Du Puy 1993).