318 NEW ENGLAND TREES IN WINTER. 



generalized features of a tree in the landscape which may be 

 recognized at a distance, but which are difficult of analysis. 



BAEK Although it is upon the appearance of the bark more 

 than upon any other character that the woodsman depends in his 

 recognition of timber trees, the bark shares with the habit the 

 misfortune of being difficult of precise description. A study of 

 the photographs, however, in connection with the description of 

 the color and texture will enable one to recognize a large propor- 

 tion of our trees by the appearance of the bark alone. They 

 have been taken from mature trees of moderate size which have 

 developed the characteristic sculpturing of the bark rather than 

 from those of larger size which are less frequently seen. A tape 

 measure surrounding the trunk or in some instances a penknife 

 stuck into the bark may serve to give an idea of the relative size 

 of the markings on the trunk. The heading "Bark" is used 

 throughout the descriptions in reference to the trunk and larger 

 limbs and not to the twigs which are described under another 

 heading. 



The color of the outer bark is an important mark of distinction 

 and is the chief means of separating the different species of the 

 Birches (p. 415-425). The color and taste of the inner layers 

 of the bark are in some cases also characteristic. The Black 

 Oak for example is best distinguished from other Oaks by the 

 yellow and intensely bitter inner bark. Similarly, the 

 Black Birch, the Sassafras and the genus Prunus including 

 the Cherries have barks with characteristic flavors. The swamp- 

 loving Poison Sumach (p. 529) is the only poisonous tree 

 in New England so that after this shrubby form is known there 

 need be no fear of tasting bark and twigs of any unknown tree- 

 like species. 



The bark varies in character according to the age of the tree. 

 In the young tree the bark is smooth, but, as the trunk expands 

 from the growth of the wood within, the covering of dead bark 

 outside is forced to crack in a variety of ways giving rise to 

 characteristic fissures and ridges which become more prominent 

 as the tree grows older. The bark of few trees such as the Beech 

 (p. 429) and the American Hornbeam (p. 413) remain smooth, 

 their outer layers expanding with the growth of the tree. The barks, 

 of others as the Paper and Yellow Birch (p. 417) stretch and peel 



