96 BETULACE.E. Betula. 



A small tree, 6 to 9 metres iu height, with a trunk 0.30 to 0.15 metre 

 in diameter ; dry, gravelly, barren soil, or borders of swamps. 



Wood light, soft, not strong, close-grained, liable to check in drying, 

 not durable ; medullary rays numerous, obscure ; color light brown, the 

 sap-wood nearly white ; largely used in the manufacture of spools, shoe- 

 pegs, wood-pulp, etc., for hoop-poles and fuel. 



The bark and leaves, as well as those of B. papyrifera and B. lenta, 

 are popularly esteemed as a remedy for various chronic diseases of the 

 skin, bladder, etc., and in rheumatic and gouty complaints ; the empyreu - 

 matic oil of birch obtained from the inner bark by distillation is used 

 externally and internally for the same purposes. 



295. Betula papyrifera, Marsh. 



Canoe Birch. White Birch. Paper Birch. 



Northern Newfoundland and Labrador to the southern shores of 

 Hudson Bay, and northwest to the Great Bear Lake and the valley of 

 the Yukon River, Alaska, south, in the Atlantic region to Long Island, 

 New York, the mountains of northern Pennsylvania, central Michigan, 

 northeastern Illinois and central Minnesota ; in tiie Pacific region south 

 to the Black Hills of Dakota, the Bitter-root Mountains and Flathead 

 Lake, Montana, northern Washington, and the valley of the lower Fraser 

 River, British Columbia. 



A tree 18 to 24 metres in height, with a trunk 0.G0 to 0.90 metre in 

 diameter; rich woodlands and banks of streams; very common in the 

 northern Atlantic region, and reaching a higher latitude than any deciduous 

 tree of the American forest. 



Wood light, strong, hard, tough, very close-grained, compact; medullary 

 rays numerous, obscure ; color brown tinged with red, the sap-wood nearly 

 white ; largely used in the manufacture of spools, shoe lasts and pegs, in 

 turnery, for fuel, wood-pulp, etc. 



The very tough, durable bark, easily separated into thin layers, is 

 impervious to water, and is largely used in the manufacture of canoes, 

 tents, etc. 



296. Betula occidentalis. Hook. 

 Black Birch. 



British Columbia, south to northern California, and through the 

 interior ranges and Rocky Mountains to Montana, Utah, and northern 

 New Mexico. 



A small tree, 8 to 12 metres in height, with a trunk sometimes 0.30 to 

 0.45 metre in diameter; mountain canons and borders of streams, in moist 

 soil, often throwing up several stems from the ground and forming dense 

 thickets. 



