S. natans ou S. molesta ? S. molesta, seule espèce présente aux Mascareignes.
Descriptif de Salvinia natans
Wikipedia
SalviniaSég.
Salvinia est un genre de fougères aquatiques qui fait partie de la famille des Salviniacées. On compte aujourd'hui une dizaine d'espèces dans le monde majoritairement dans des régions tropicales.
Le mot Salviana est dédié à un professeur de grec, Antonio Maria Salvini (1653-1729).
Le genre Salvinia est caractérisé par des feuilles munies de papilles hydrofuges et l'absence de racines.
https://fr.wikipedia.org/wiki/Salvinia
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Small, floating aquatics with creeping stems, branched, bearing hairs on the leaf surface papillae but no true roots. Leaves are in trimerous whorls, with two leaves green, sessile or short-petioled, flat, entire, and floating, and one leaf finely dissected, petiolate, rootlike, and pendent. Submerged leaves bearing sori that are surrounded by basifixed membranous indusia (sporocarps); sporocarps of two types, bearing either megasporangia that are few in number (approximately 10), each with single megaspore, or many microsporangia, each with 64 microspores. Spores of two 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. The small, hairlike growths, known as microgametical follicles, are not known to have any productive function, and are currently a biological mystery.