Scientists look at a tree for important details. They construct keys to help them identify trees based on the tree's characteristics. The keys don't include every tree, just those in a given region. To use a key, you answer a series of questions about a tree. The answer you choose brings you to another question. Each question becomes more specific until you reach the identity of the tree.

To learn more about how keys are used to identify trees:

1. Go to the Name That Tree WWW Sheet and print it.

2. Visit these Web sites. Then complete the WWW Sheet.
    Tree Leaves
    An Interactive Key of Common Iowa Trees