ABSTRACT
Leaves are porous inside, occupied by cells with air gaps and passageways to the leaf stomata. Transpiration is the process whereby liquid water evaporates from the surface of cells within the leaf into the leaf air-space and diffuses to the outside through stomata. Stomata are pores on the surface of the leaf that are formed by two guard cells. These guard cells distort to cause the stomata to open in the presence of light and decreased intercellular leaf concentration of CO2.
