Small, free-floating, aquatic ferns, capable of rapid vegetative reproduction by fragmentation and forming a carpet on still water. Rhizome horizontal, freely branching, bearing uniseriate, multicellular haris, lackign roots, vascular system a poorly developed, medullated protostele. Leaves shortly stipitate, in whorls of 3, 2 leaves of each whorl entire, broadly round-oblong, and floating on the water surface, costate with simply veins anastomosing at the margin, papillate above, the papillaie bearing 4 multicellular hairs, often apically united, smooeth with straight multicellular hairs below; the third leaf finely dessected into a cluster of long thing branches bearing numerous uniseriate multicellur hairs, submerged and root-like; vernation straight. Sporangia borne in sporocarps, the sporocarps in groups on the branches of the root-like leaves, quite enclosed in a thinkg globose indusium bearing multicellular hairs, receptacle much-branched, bearing either megasporangia or microsporangia; megasporangia few, large, each containing a single megaspore, microsporangia many, small, each containing 64 microspores. Spores globose, trilete.
Species in Papuasia
|A single species in Papuasia...||S. molesta|