Leaves that move.

These are the leaves of the false shamrock Oxalis triangularis widely grown as a pot plant but endemic to Brazil where it is on the IUCN REd List of endangered species. The photograph is a composite showing the same leaf during the day (left) and at night (right).

The leaves open and close in response to light levels, opening in high ambient light and closing at low light levels. The movement is not due to growth but instead is powered by changes in the turgor pressure of the cells at the base of the leaf. You can see the leaves in action in this short video.