The Pistia genus appears to contain only one species. It is a floating plant
which grows rather slowly, but it is of great interest to aquarists.
The leaves of the water lettuce have a velvety sheen. This plant needs strong
lighting to grow and for seedlings to form on the runners. It provides an aquarium
with shade and a refuge for fry. It is badly affected by drops of water formed by
condensation on the lid of the tank. Diameter: 5-6 cm.