We can group them by age.

Scales of a Cone

Trees that grow cones are in a group called conifers. The cones of the conifers are very important because they are the place where the tree makes and shelters its seeds.

Cones are made up of many scales. Scales are a kind of shelter for the seed. When it's time, the scales of the cone open and the seeds fall to the ground. Because the seeds sit on the scales and are not totally protected, conifer trees can also be grouped as gymnosperms. The word gymnosperm means naked seed.

Another way to group trees is by the kind of leaves they have. Some trees have broad-leaves. Broad leaves have large surfaces so they can gather a lot of sunlight. A tree with flat, wide leaves also loses a lot of water because of evaporation.

There are other trees that have needle-like or scale-like leaves.

Maple trees have
broad leaves.

You can also group trees by how they lose their leaves. Many trees lose their leaves when the weather gets cool. On these

This conifer is an evergreen.

trees, the leaves fall to the ground all at once and grow back again when the weather gets warmer. Many trees with broad leaves do this. We call them deciduous trees.

Other trees have leaves or needles that fall off a little at a time. These types of trees are always growing new leaves. As the old ones fall off, they are replaced. We call these trees evergreens.