In some plants that have leaves that receive too much sunlight the stomata concentrate in the inferior epidermis, so their heating is lower and less water is lost by stomatal transpiration. In other plants of dry environments the stomata group in some regions of the leaf; over the surface of these areas the water concentration of the air is higher comparing to the environment and the loss of water by transpiration is thus reduced. Some plants of dry climates also have stomata within cavities.
