58 



fewer than twenty-five are important for timber-producing purposes. 

 Many inferior species which have little present or prospective value 

 have been introduced into this publication, since it was thought just 

 as important to know what not to plant as to know what to plant. 

 Some species may not be valuable for the production of timber but 

 they may have a value as shelter to other species or as soil pro- 

 tectors and soil conservers. Many species which cannot be regarded 

 as final members of a timber-producing forest may be of temporary 

 value in helping to establish the more valuable permanent species. 

 We should be cautious in eliminating the inferior species from our 

 forest structure, because they may possess a value which is not evi- 

 dent at the present time. It should be remembered that the species 

 despised by myself may be prized by my neighbor, and that the 

 species despised today by my neighbor and myself may be prized 

 by both of us tomorrow. Only general statements are made with 

 reference to the importance of the species. A fuller discussion of 

 this heading may be found in any standard text on General Forestry 

 or Silviculture. 



How TO Identify the Species and Use the Keys: 



Since this publication is intended primarily for laymen and for 

 students who are just beginning the study of trees, the omission of 

 technical terms was thought advisable. We have many species of 

 trees, some common, others uncommon, which the average layman 

 may not know. He can learn them readily if their distinguishing 

 characteristics are presented to him in ordinary language accom- 

 panied by simple and exact drawings. This publication is designed 

 so that the average layman with even a limited knowledge concern- 

 ing trees can use it and identify the various species with little, if 

 any, diflBculty. 



The procedure or method of identification varies with the indi- 

 vidual. One may take material from a tree and compare it with 

 the drawings until he finds one with which it corresponds or to which 

 it fits, and then feel satisfied that he has learned to know the tree. 

 To check himself and to acquire additional information he may read 

 over the descriptive material accompanying each plate. This method 

 of comparison witb plates, while the one commonly used by laymen 

 who have little or no working knowledge concerning trees, is labor- 

 ious and entirely unscientific. A better and yet simple method is the 

 use of an analytic key for the identification of the species. Such keys 

 according to their construction may be simple or complex, service- 

 able or unserviceable to the average layman. In constructing the 

 subjoined analytic key, an attempt was made to make it simple and 

 yet exact, based upon permanent rather than transient, and constant 



