Description: Small aquatic ferns, free-floating; rhizome short-creeping, bearing hairs but no roots; vernation not circinate.
Fronds borne in whorls of 3, dimorphic; each whorl of 2 foliar leaves and the third much divided, root-like and submerged.
Sori arising on submerged divided leaves, each enclosed in an indusium, forming a sporocarp; sporangia of 2 types, microsporangia numerous, megasporangia few; spores dimorphic.
Distribution and occurrence: World: 10 species, widespread in tropical & subtropical regions. Australia: 1 species (naturalized).
Characters and distribution as for family.
Text by Peter G. Wilson
|One species in NSW: Salvinia molesta|