thinksciencemaurerImage: thinksciencemaurerDichotomous Tree Identification Key. "Dichotomous" means "divided into two parts.". Therefore,a dichotomous key will always give you two choices in each step and following all the steps will lead you to the name of the tree you're identifying. 1) Use the leaves from a treeor find a picture of a tree you want to identify and click on the most appropriate match to the right. Dichotomous Tree Identification Key - University of Wisconsin Was this helpful?