[2] Twelve species are recognized, at least three of which (S. molesta, S. herzogii, and S. minima) are believed to be hybrids in part because their sporangia are found to be empty.

The upper side of the floating leaf, which appears to face the stem axis, is morphologically abaxial.

[4] Small, floating aquatics with creeping stems, branched, bearing hairs on the leaf surface papillae but no true roots.

(Kariba weed) S. oblongifolia von Martius Other species include: The geography of Salvinia fossil material suggests members of the genus may have been broadly distributed during the Tertiary.

This physic-chemical phenomenon was discovered on the floating fern Salvinia molesta by the botanist Wilhelm Barthlott (Universität Bonn) while working on the Lotus effect and was described in cooperation with the physicist Thomas Schimmel (Karlsruher Institut für Technologie), fluid mechanist Alfred Leder (Universität Rostock) and their colleagues in 2010.