Plants adapted to areas where water availability is very limited are called Xerophytes. They have special structural modifications to reduce the loss of water by transpiration. These include the placing of stomata within pits so that they do not lie on the wind swept surface, the development of hair like structures called trichomes on the leaf areas where the stomata are positioned, this causes a layer of still air to be trapped over the stomata.

More advanced features occur in Cacti.

These features include:

1. Reduction in leaf size and the development of photosynthetic stems which are swollen to store water.
2. The development of a thicker layer of waxy cuticle to waterproof the stem.
3. Changes to the diurnal opening and closing cycle of the stoma, they open at night to allow the diffusion of CO₂ into the stem, this CO₂ is then chemically trapped, then during the day when it is hot, the stoma remain closed and the stored CO₂ is used for photosynthesis within the succulent stems.

Some plant have leaves which roll up into a tube shape when water becomes scarce, but open to a flat shape when water is plentiful. This is done by the change in osmotic pressure of groups of balloon like cells which hold the leaf flat when they are inflated but cannot resist the tension of the elastic cuticle when they start to deflate due to evaporative loss of water.