Plant Parts - Leaves

Leaves are the food making factories of green plants. Leaves come in many different shapes and sizes. Leaves can be simple. They are made of a single leaf blade connected by a petiole to the stem. An oak leaf or a maple leaf is examples. A compound leaf is a leaf made up of separate leaflets attached by a petiole to the stem like an ash or a locust.

Leaves are made to catch light and have openings to allow water and air to come and go. The outer surface of the leaf has a waxy coating called a cuticle which protects the leaf. Veins carry water and nutrients within the leaf.

Leaves are the site of the food making process called photosynthesis. In this process, carbon dioxide and water in the presence of chlorophyll (the green pigment) and light energy are changed into glucose (a sugar). This energy rich sugar is the source of food used by most plants.

Photosynthesis is unique to green plants! Photosynthesis supplies food for the plant and oxygen for other forms of life.