In his publication,Deciduous Trees& Shrubs of Central Minnesota, Stephen G. Saupe, Ph.D., biology professor, has offered silhouettes of some of the common species in Minnesota as well as throughout North America. These diagrams were designed to help his studentsstudy leaf form. Here are some ...
Look at the placement and size of the thorns. Long, straight or slightly curved thorns on the branches indicate a Hawthorn. Short to medium-length straight thorns indicate the Osage orange. Honey locust thorns are branched, and are found in clusters on the trunk. Russian olive tree thorns are...