Plant Identification: Making A Plant Dichotomous Key - The Oct 14, 2018Dichotomous key. A dichotomous key is guide, sort of like a map of characteristics, to lead the user to the correct identification of the plant. The word dichotomous comes from two Greek words that mean divide in two parts. To make a dichotomous key you will choose physical characteristics that can be used to divide a collection into two parts.[PDF] Animal Classification Using a dichatomous key Animal classification Using a dichotomous key Background: Classification of animals is a way to group them based on similar traits. This is an important way to see how animals are related to each other. They are separated into groups using traits or characteristics (like whether they have a backbone or not).