TREES

Tree is the largest of all plants. The tallest trees grow higher than 30-story buildings. Many trees also live longer than other plants. Some trees live for thousands of years. They are the oldest known living things.

People do not think of trees the way they think of other plants, most of which grow only a short time and then die. People think of trees as permanent parts of the landscape. Year after year, large, old trees shade houses and streets from the sun. Their buds and flowers are a sign of spring each year, and their colorful leaves brighten in autumn in many areas.

Trees continue to grow as long as they live. A tree's leaves make food that keeps the tree alive and helps it grow. Where winters are cold,...