The primary functions of a leaf are :
1.The most important function of leaves is the synthesis of organic food through photosynthesis.
2.Leaves possess minute pores called stomata. The stomata help in the exchange of gases necessary for photosynthesis and respiration.
3.Leaves are the main seat of loss of water called transpiration. Transpiration provides necessary force for the ascent of sap and keeps the temperature low in summer.
4.Leaves protect the axillary and terminal buds from mechanical injury and dessication.