Terrestrial or epiphytic
fern-allies. Rhizome none or, if present creeping, prostrate, procumbent,
monopodially branched, covered with hair. Stipe aerial, scandent repeatedly
forking up to 3-4 times, rooting at intervals.
Fronds small simple, triangular, ovate- lanceolate in shape. Vegetative
fronds iso-, di-, or trimorphic or sometimes adnate ultimate branches flat with
tetrastichous fronds or round with spiral fronds. Sporophyll in distinct
strobili up to 2-3 cm long, sessile or peduncle. Sporangia axillary along the stipe or
aggregated in terminal spikes in the axils. Spores two kinds, megaspore and
microspore, uniform, globose, granulate without
elaters nearly round, regulate, reticulate, subglobose or subtringular.