Each leaf brings food to the tree such as energy from the sun and create carbohydrates from water and carbon dioxide in the air. Trees produce oxygen. Trees grow very very slowly. The blade or lamina is the broad flat part of the leaf. Leaves have two main parts, the blade and the petiole or leafstalk.
Some leaves have a third part called the stipules.
Petiole is the stemlike part of the leaf. Stipules are two small flaps at the base of the leaf. Transpiration happens when the sun warms the water inside the blade. This process helps cool the inside of the leaf. A leaf is green because it has pigment called chlorophyll.