Parts of a Leaf

A leaf is a plant part that makes food for the plant. Inside and outside a leaf, there are special parts that each do an important job. Understanding these parts helps us see how plants stay alive and healthy.

The outside of a leaf has a waxy coating called the cuticle. This coating is like a raincoat for the leaf. It keeps water inside the plant so the leaf does not dry out. Without this coating, the plant would lose too much water and die.

On the bottom side of most leaves are tiny openings called stomata. These openings are so small you need a microscope to see them. Stomata let air move in and out of the leaf. Plants need air to make food and to release the oxygen we breathe. The stomata can open and close like tiny doors to control how much air and water vapor moves through them.

Inside the leaf are green cells that contain chloroplasts. Chloroplasts are tiny structures that capture sunlight. They use the sun's energy, along with air and water, to make food for the plant. This is why leaves are usually green—the chloroplasts give them their color. Each part of the leaf works together to help the plant survive and grow.

Interesting Fact: A single leaf can have thousands or even millions of stomata on its underside, and they open during the day to let air in and close at night to save water!