The species selected for this study differ greatly in their functional traits: Aldrovanda and all Utricularia species are rootless, mostly submerged, carnivorous plants; Hydrocharis is a free-floating plant with roots and Caldesia is a typical rooted amphibious species. Except for Caldesia, all species usually germinate and sprout at the water surface, while Caldesia germinates, sprouts and roots at the bottom. After collection from the cultures between the end of September and mid-November, ripe turions of all species were washed using tap water and stored in the dark in the filtered cultivation medium in a refrigerator at 2.5 ± 1 °C until used.