Aldrovanda vesiculosa is an aquatic plant. The genus Aldrovanda (Water Wheel Plant) has only one species, which is to be found worldwide. It is closely related to the Venus Flytrap (Dionaea muscipula) and applies like this a snap trap mechanism for prey catching.
Aldovandas produce a swimming, circa 20 cm long sprout with numerous leaf whorls. From the whorls arise ordinarily between 5 – 10 bristles, which for their part carry circa 5 mm large snap traps (morphological those of the Venus Flytrap very similar). With the snap traps the Aldrovanda preys small water fleas, mosquito larvae and the like.
Up to circa 20 years ago a longer-term culture of Aldrovanda was considered to be almost impossible. In the meantime several tricks have been found, with which Aldrovanda is to cultivate relative trouble-free and easy for years. Up to now I collected experience only in the culture of the non-frost-hardy clone ‚Sydney‘. As culture pot is suitable a small transparent bowl or a small aquarium with a volume of circa 3 – 10 l with a water level of 5 – 10 cm. The goodness of water as well as of the soil are very important. Avoid an overmuch nutritional supplement, an alga growth on the Water Wheel Plant is lethal! I use as soil a mixture of raised bog peat, lime-free quartz sand as well as a driblet clay (circa 5%). I add to the soil a driblet sedge leaves as well as a small potsherd. Both is important! From the potsherd are trace minerals like boron released, the sedge leaves decay slowly and release continually a few carbon dioxide, which Water Wheel Plants need for their growth. In addition I ‚inject‘ the water with a few water fleas and ditch the pot for circa one month at a slight half-shady place. If a stable equilibrium has arrived after one month and if the pot doesn’t show any alga growth, then I add the Water Wheel Plants. Mostly I add furthermore one Eichornia. Eichhornias are water hyacinths, which are subject to a fast growth and thereby absorb rapidly nutrients and convert them into biomass. You get water hyacinths in fishkeeping shops or in summer in the pond division of a garden centre. The only disadvantage of Eichornias is their distinct root system, in which Water Wheel Plants are often caught. This is then a problem, if you want to remove abundant Eichhornias from the aquarium. Thus, I partition the Eichhornias from the Water Wheel Plants mostly with an additional transverse glass panel, which is slight smaller than the pot, so that a water exchange between both section is ensured. An all-year culture on the windowsill is possible.