TREES AND SHRUBS OF THE UNITED STATES 

 A Bibliography for Identification 



By Elbert L. Little, Jr. , and Barbara H. Honkala ' 

 INTRODUCTION 



"Where can I find information about this tree (or shrub)?" is a question 

 frequently asked. The purpose of this bibliography is to help with the 

 answer. 



The first step in obtaining information about any tree or shrub is to 

 learn its name. The scientific name is the key to unlock the door of all 

 records preserved in storage. Once a plant is identified, the wealth of 

 information that has been printed through the years and cataloged in 

 libraries becomes accessible. 



Selected references have been compiled for identification in the United 

 States of wild and cultivated trees, shrubs, and woody vines, together 

 known as woody plants. This list of more than 470 titles should be useful 

 to persons interested in plant resources, including foresters, botanists, 

 conservationists, researchers, librarians, teachers, and students. This 

 publication supersedes "United States Tree Books, a Bibliography of 

 Tree Identification" (Dayton 1952 A 2 ), which has long been out of print. 



Names of most wild trees and shrubs can be found in the popular guides 

 and handbooks listed by States and regions. For additional identification, 

 technical references are available. If needed, further assistance may be 

 sought from specialists in plant identification. Plant taxonomists, or 

 taxonomic botanists, are located in departments of botany and forestry of 

 universities and colleges and in State agricultural experiment stations, 

 botanical gardens, arboreta, herbaria, and museums. 



Definitions. It is convenient to treat woody plants together in re- 

 ferences, because the kinds or species differ mostly in size and habit and 

 are not sharply separate. Woody plants have hard stems and branches 

 which are composed of wood tissue and are perennial, surviving through 

 winters. A tree is a woody plant with one erect perennial stem or trunk (at 

 least 3 inches or 7.5 centimeters in diameter at breast height, 4M> feet or 

 1.4 meters), a more or less definitely formed crown of foliage, and a 



1 Chief dendrologist and research botanist, respectively, Timber Management Research, 

 Forest Service, United States Department of Agriculture, Washington, D.C. 20250. 



2 Names, dates, and letters refer to the lists designated by letter (see Contents) and 

 arranged alphabetically by authors. 



