Besides Dionaea, what other carnivorous plant genus uses snap traps?

Besides Dionaea, the other carnivorous plant genus that uses snap traps is Aldrovanda.

Aldrovanda is best known through its living species, Aldrovanda vesiculosa, commonly called the waterwheel plant. Unlike the terrestrial Venus flytrap, it is aquatic and floats in still or slow-moving freshwater. Its tiny paired trap lobes close around small invertebrates, especially zooplankton.

The mechanism resembles a miniature Venus flytrap: trigger hairs detect movement, an electrical signal spreads through the trap, and the lobes flip from an open convex shape to a closed concave one. The trap can shut in roughly 0.01–0.02 seconds. Small bristles and additional teeth help keep debris from triggering the trap and prevent prey from escaping.

For much of the twentieth century, scientists thought Dionaea and Aldrovanda might have evolved snap traps independently. Molecular studies published in 2002 instead indicated that the two genera are close relatives and that the snap-trap adaptation evolved once in their common ancestor. Both belong to the family Droseraceae, which also includes sundews, although sundews use sticky flypaper traps rather than snapping leaves.