Salvinia molesta Mitchell propagates vegetatively by proliferation. Spores are nonviable. Mechanical disturbance enhances the rate of proliferation. The rates of proliferation within 30 days are 1: 8 in agitated media and 1: 1 · 6 in intact media under laboratory conditions. While the frequency of addition of fresh set of leaves ranged between 3–18 days in the natural habitat it was between 3–9 days under the laboratory condition. Crowding ofSalvinia is a prerequisite for the cessation of proliferation and initiation of the final ‘grown up stage’.Salvinia of ‘floating stage’, ‘intermediate stage’ and ‘grown up stage’ have different density ranges such as 765–986, 942–1280, and 65–345/m2 and biomass ranges of 18–25, 50–70 and 340–375 g dry wt./m2 respectively under natural conditions.