Leaves and trees

Summer's here, and everything is blooming and green. Leaves do more than add color to our world. They carry out a very important job for plants: making food. This process is called photosynthesis (foh-toh-SIN-theh-siss). During photosynthesis, leaves absorb the sun's energy. They also take in gas from the air called carbon dioxide (dye-oX-ide). The sun's energy and carbon dioxide chemically combine with water inside the leaf. This creates a sugary food for the plant. Most leaves have three basic parts:

Leaves are the first thing we notice about trees, and tree leaves come in many different shapes. Trees are divided into two basic groups based on the shape of their leaves. Conifer trees, also called evergreens, grow needle-shaped leaves. Conifers don't lose their leaves in fall. Deciduous (de-SIDJ-oo-uss) trees, also called broadleaf trees, grow wide, flat leaves. Deciduous trees do lose their leaves in fall. You can identify trees by the shape of their leaves. For example, leaf edges may be smooth, toothed or lobed (finger-like). Leaves may grow singly or in groups called leaflets. Look at the Leaf ID Chart to learn more. Then, take a quiz to test your leaf smarts!