There are small openings on the lower surface of the leaves. These pores are called stomata. These openings are surrounded with guard cells.

Functions of stomata:

1. It helps in the transpiration of water, i.e., the loss of excess water from the plant.

2. Loss of water from the stomata creates an upward pull, i.e., suction pull which helps in absorption of water from the roots.

3. They help in exchange of gases.