BIRCH FAMILY 



Others are var. pendula, weeping ; var. fastigiata, pyramidal ; 

 var. pubescens, leaf covered with white down. All are 

 beautiful. 



PAPER BIRCH. CANOE BIRCH. WHITE BIRCH 



B^tula papyri/era. 



Widely distributed over a northern range. Sixty to seventy feet 

 high. When young forming a compact pyramidal head, in old age 

 becoming a branchless trunk, supporting a round-topped open head 

 of pendulous branches. Prefers rich moist hillsides, borders of 

 streams, lakes, and swamps. Sap flows freely in spring and by boil- 

 ing can be made into syrup. 



Bark. — On old trees, near the ground, dark brown or nearly 

 black, sharply and irregularly furrowed. At the base of young 

 trees, brown tinged with red, separating irregularly into large plates. 

 Higher on the trunks of old trees, on young stems and large limbs, 

 creamy white, shining on the outer surface, bright orange on the 

 inner, marked with horizontal lenticels and separating freely into 

 thin papery layers. Branchlets slender, hght green, then orange 

 and finally through red and brown in the course of years they be- 

 come white. Bark contains not only an astringent principle but a 

 resinous balsamic oil. 



IVood. ^'L\ght brown tinged with red ; light, hard, tough, close- 

 grained and strong. Used for spools, shoe-lasts, wood pulp, fuel. 



Sp. gr., 0.5955 ; weight of cu. 



ft., 37.11 lbs. 



Winter Buds. — Ovate, 

 acute, dark brown, resinous, a 

 quarter of an inch long. 



Leaves. — Alternate, simple, 

 two to three inches long, one- 

 half to two inches wide, ovate, 

 heart-shaped or rounded or 

 wedge-shaped at base, coarsely, 

 doubly, or irregularly serrate 

 with spreading teeth, abruptly 

 acuminate; midrib slender, 

 yellow, raised and rounded, 

 and marked with minute black 

 glands. They come out of the 

 bud bright green, pubescent, resinous ; when full grown are thick, 

 firm, dull dark green above, pale yellow green beneath, covered with 

 minute black glands. In autumn they turn clear pale yellow. 



302 



Paper Birch, Belula papyrifera. Strobiles pen- 

 dulous, -r%' to 2' long. 



