A tree is a tall plant with a trunk and branches made of wood. Trees can live for many years. The oldest living tree found is about 5,000 years old. The oldest tree from the UK is about 1,000 years old. The four main parts of a tree are the roots, the trunk, the branches, and the leaves. Trees are a wide variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight.