BIRCH FAMILY 



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This description, " to float at the discretion of the winds," 

 admirably characterizes the attitude of the White Birch. 

 The white stem rises unbroken to the summit of the tree, 

 the branches come out at a large angle, go out horizontally, 

 or perhaps dip a little and divide into branchlets so long, 

 slender, and delicate that they have no rigidity but yield to 

 every impulse of the passing breeze. The leaves flutter as 

 freely as those of the Aspen for the petioles though not lat- 

 erally compressed are long, slender, and slightly twisted, 

 which puts the leaf into such unstable equilibrium that it re- 

 sponds to the lightest motion of the air. 



The outer layer of the bark is thin and white, both on the 

 stem and larger limbs, but neither it nor the inner layer will 

 separate from the wood as easily as will that of the Canoe or 

 Paper Birch. A marked characteristic is the triangular black 

 spots appearing on the trunk beneath every limb as well as 

 in other places. 



Although the wood quickly decays in contact with the 

 earth, the bark under similar conditions remains unchanged. 

 This is due to a peculiar resin found in the bark which ren- 

 ders it impervious to water. 



The tree loves rocky barren woods, old fields and aban- 

 doned farms, and in New England has the familiar name of 

 Old Field Birch. It is the least common of all the birches 

 and is rarely found growing in groups. It is plainly unable to 

 hold its own in competition with other trees, and is found 

 largely on exhausted sandy soils where other trees are unable 

 to grow. When planted, however, it does not disdain moist, 

 fertile land and acts as an excellent nurse for other trees, but 

 under no conditions is it long-lived. 



The Gray Birch so closely resembles the common Euro- 

 pean birch, Betula alba, that it has by some botanists been 

 classed as a variety of that species. However, it grows with 

 less vigor and does not attain so large a size. 



The European Birch appears in American lawns and parks 

 principally in its cultivated varieties. The most common 

 of these is Betula alba var. laciniaia^ the cut-leaved Birch. 



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