Epiphytic, terrestrial or epilithic ferns. Rhizome slender and long
creeping. Fronds with many shapes, very small and simple to fairly large,
highly divided, the ultimate divisions always small, in cases one veined.
Lamina one celled thickness, only in a few species there are flat thickened
band on either side of the veins. Sori terminal on the ultimate one-veined
lobes, or marginal at vein-endings on the base of the enclosed in the tubular
or conical hollow base of the indusium, the apical part of the indusium more or
less dilated, often more or less deeply divided into two lips. Sporangia with
the oblique annulus.