Forest Trees of Illinois (Third Edition) — Reading Companion

Forest Trees of Illinois

By Robert H. Mohlenbrock Department of Botany, Southern Illinois University

Photography by John A. Richardson and Robert H. Mohlenbrock Illustrations by Miriam Wysong Meyer and Fredda J. Burton Southern Illinois University

Printed by authority of the State of Illinois Issued by DEPARTMENT OF CONSERVATION Division of Forestry

Acknowledgments 4 Introduction 5 Illustrated Glossary 6 Key to the Trees of Illinois in Spring, Summer, and Fall 9 Key to the Trees of Illinois in Winter 27 Trees of Illinois 38 Special Places to Study Trees 318 White Oak, the State Tree of Illinois 322 Illinois Big Tree Champions 323 Index to Common and Scientific Names 324 District Foresters 330

I am grateful to the late Mr. Fred Siemert, State Forester of the Illinois Division of Forestry, for suggesting the need for a new “Forest Trees of Illinois.” The first and second editions of this work have been immensely popular, and the need for a third edition is gratifying.

This third edition is only slightly modified from the second. A few illustrations and bark photographs have been substituted, and the key has been improved in places. New material has been added to the description of the water hickory.

I wish to give thanks to Mr. Al Mickelson of the Illinois Division of Forestry for encouraging this third edition, and to his assistants, Mr. John Sester and Mr. Ernest Kunze, for editing it for publication. Mark Mohlenbrock has redrawn the leaves and fruit illustrated on pages 101 and 169.

The initial edition of Forest Trees of Illinois was written in 1927 by W. R. Mattoon and R. B. Miller, two prominent foresters in the state at that time. This was revised in 1955 by Dr. George Damon Fuller, then of the Illinois State Museum, and E. E. Nuuttila, State Forester of Illinois.

In 1973, I prepared the first edition of the new Forest Trees of Illinois with new text, keys, photographs, and illustrations. An updated second edition was published in 1978. Because of the heavy demand for this work, this third edition has been prepared.

Woody plants are usually divided into trees and shrubs, but the difference between these growth forms is not always distinct. In this work, we consider a plant to be of tree stature if it has a single erect trunk which branches above the ground to form a crown. It must have a diameter of at least 3 inches 4½ feet above the ground and an overall height of 12 feet. Some of the plants included in this work are borderline between trees and shrubs. The height of a plant may be influenced by its geography. Thus, the Gray Dogwood (_Cornus racemosa_) in extreme southern Illinois may reach the dimensions of a small tree, but this same species in northern Illinois is also of a shrubby stature.

Almost every kind of plant in the world is known by a Common Name and a Latin Name. The Common Name is the one used locally by residents of the area. It is of limited value because people in different areas sometimes have different names for the same plant. For example, one of the trees in Illinois is known by some as the Ironwood, by others as the Blue Beech, by others as the American Hornbeam, and by still others as the Musclewood Tree. Then again, the name Ironwood applies to at least two different kinds of trees in Illinois. The Latin Name for each kind of tree is known the World over by the same name. Actually, the Latin Name is composed of two words, the genus name, which is always capitalized, and the specific epithet, which is not capitalized.

Of all the kinds of plants in the World, none is so well-loved, so stately and majestic, as a forest tree. More and more people each year are vacationing and seeking outdoor recreation. Many of them “take to the woods” for their leisure, because the forests of our state hold an unending fascination to many who enter them.

Moreover, trees provide us with building material for our homes, shade for our lawns and parks, and hundreds of other products used in our everyday living.

To know the trees we encounter is to enhance our appreciation for them. The purpose of FOREST TREES OF ILLINOIS is to bring to Illinoisans a means of identifying the trees that grow in this state.

In order to distinguish one kind of tree from another, it is necessary to learn the major characteristics which the forest trees of Illinois may possess. Illustrated below are several of the most commonly encountered characteristics of leaves and twigs. A thorough understanding of these structures will insure a quicker and more accurate identification.