The Water Wheel, Aldrovanda vesiculosa, has traps quite similar to Dionaea, Venus Flytrap. This active-trapped CP is less known and often difficult to obtain. It grows much like the bladderworts, and in similar acidic peaty waters with surface cover. It consists of a rootless stem with leaves arranged like spokes on a wheel. Each whorl consists of eight leaves about a half inch long with traps at the tips that closely resemble the Venus Flytrap. There are about forty trigger hairs. It grows near the surface of freshwater, acid swamps in tropical and temperate regions. Its range extends from Europe and Africa to Japan and Australia.
There are introduced populations in Lake Oswassa, NJ, and Fort AP Hill, VA.