Plants small, floating aquatics. Stems creeping, branched, bearing hairs but no true roots. Leaves in whorls of 3, with 2 leaves green, sessile or short-petioled, flat, entire, and floating, 1 leaf finely dissected, petiolate, rootlike, and pendent. Submerged leaves bearing sori that surrounded by basifixed membranous indusia (sporocarps); sporocarps of 2 types, bearing either megasporangia that few in number (ca. 10), each with single megaspore, or many microsporangia, each with 64 microspores. Spores of 2 kinds and sizes, both globose, trilete. Megagametophytes and microgametophytes protruding through sporangium wall; megagametophytes floating on water surface with archegonia directed downward; microgametophytes remaining fixed to sporangium wall.

Distribution

Mostly tropical, North America, Mexico, West Indies, Central America, South America, Eurasia, Africa including Madagascar.

Discussion

Genus 1, species 10 (1 species in the flora).

Selected References

None.

Lower Taxa

Salvinia

Illustrations

	Family ⠉	Taxon	Illustrator ⠉
	Azollaceae Azollaceae Azollaceae Salviniaceae	Azolla filiculoides Azolla mexicana Azolla caroliniana Salvinia minima	John Myers John Myers John Myers John Myers