2 MISCELLANEOUS CIECULAR 92, U. S. DEPT. OF AGRICULTURE 



recognized, and during the past quarter of a century many popular 

 books applying particularly to eastern United States have appeared. 

 There is still need, however, for such literature dealing with the 

 trees of other parts of the country. In addition to these popularly 

 written books on trees, there are a number of technical works avail- 

 able, of which some deal with all of the plants (trees, shrubs, and 

 herbs) of certain large sections of the country, and one or two are 

 devoted only to the trees of North America (north of the Mexican 

 boundary). Thousands of intelligent laymen, keenly desirous of 

 knowing the trees of their locality, county, or State, are unable 

 fully to help themselves by means of this literature, and chiefly 

 because they have neither the time nor the opportunity to acquaint 

 themselves with the technical language of such books. Obviously, 

 it is difficult accurately and concisely to describe the distinguishing 

 characteristics of plants in popular language. However, the writer 

 is confident that a very large number of laymen greatly appreciate 

 the attempts now being made to translate technical language as 

 nearly as possible into that of everyday usage. 



IMPORTANT FOREST TREES 



Of the 1,177 different trees that make up our forests, 182 are of 

 special interest either because of the commercially useful timber 

 or other products they supply, or because of their importance in 

 forestry. In order that the reader may easily distinguish the names 

 of such trees they have been marked with an asterisk (*). 



Obviously, the number of important species can not remain 

 constant, it being either increased or decreased from time to time 

 in accordance with the development of commercial needs. Thirty 

 years ago a list of the then important forest trees included about 

 100 different species. The discovery since then of new uses for wood 

 and the extension of old uses to new and untried woods have greatly 

 increased the number of native species that are now of special 

 importance. Extending the usefulness of forest trees is a process 

 that is ever going on, so that the list of trees now regarded as im- 

 portant must be considered largely as tentative. 



It is only such trees as pines, spruces, firs, and cedars, which have 

 the habit throughout their wide ranges of forming extensive pure 

 stands, or- those that form large proportions of mixed forests, such 

 as oaks, chestnut, hickories, beech, maples, and ashes, that can 

 remain fairly permanent members of a list of trees important in 

 forestry. A good many of these, even after the natural supply 

 has been greatly exhausted, as is the case with Eastern White Pine, 

 are receiving, and will receive still more, such protection through 

 Federal, State, and private conservation as will continue their im- 

 portant commercial existence. 



A few species admitted to this fist are important only in limited 

 parts of their ranges, being insignificant in size and therefore of 

 little or no commercial use over the remainder of their ranges. No- 

 table among these are Chamaecyparis lawsoniana, CJiamaecyparis 

 nooikatensis, TJmhellularia californica, Taxus brevifolia, etc. 



An interesting phase of the extended and varied new uses of 

 woods or other products of the trees, is the possible danger of early 

 exhaustion of the natural supply now available of some of the rarer 



