Handbook of Trkks of tiif. Xoktiikicx Statkh and Canada. 121 



The Paper Birt'li. west of tlie Rooky Moun- 

 tains, is said to attain a lu'lglit of 120 ft. with 

 trunk from 3-4 ft. in thii-kness, but elsewliere 

 rarely e.xceeds 70 or 80 ft. in height. When 

 isolated from other trees it develops a full 

 rounded and usually irregular top of many 

 branches. The bark of the larger branches 

 and young trunks is laiiiinatc. smooth and of 

 creamy or i\ory w hiti'Mi'ss, marked with long 

 horizontal rai.sed lenticels. As the trunk en- 

 larges the bark becomes more or less streaked 

 and blotched with blackish and the outer layers 

 separate and roll back in large ragged sheets. 

 On very old trunks the bark at base becomes 

 broken into large closely appressed irregular 

 scales. It inhabits rich slopes and ornaments 

 the banks of northern streams and lake-shores 

 from the Atlantic to the Pacific, ranging north- 

 ward to the Arctic Circle. With the northern 

 Indians its bark, impervious to water, is an 

 indispensable material for the manufacture of 

 their canoes and for many articles for domestic 

 use. 



The wood, of which a cubic foot when abso- 

 lutely dry weighs 37.11 lbs., is used in the 

 manufacture of wooden- ware, wood-pulp, etc., 

 and is excellent for fuel. 2 



Leaves ovate. 2-4 in. long, acute or acuminato 

 at apex, rounded or obtuse ( cordate in var. ronli- 

 folia Fern.) and entire at liase, doubly or ir- 

 FPfruIarly serrate, thick and firm at maturity, 

 glabrous dark green above, paler and pubescent on 

 the veins and with black glands beneath. Floircrx: 

 staminate amcnts ''j-l^i in. long in winter, fin-illy 

 ;>-4 in. lonir : pistillate aments l-H^ in. lon>?, 

 slender, with lii^ht i^reen scales and red styles. 

 Fruit: strobiles cylliKlrieal, about 1% in. long, 

 drooping, glabrous, middle lobe of scales longer 

 than broad ; nutlet much narrower than its wings. 



1. Syn. /{. jKiiii/raci u .\ . 



L'. A. \V, 



II, 4: 



