THE BALSAM POPLAR. 



The Balsam Poplar {Populus balsamifera, Linn.), is found 

 growing commonly throughout the Northern United States and 

 Canada, but it reaches its greatest development in the north, 

 especially along the Mackenzie River and its tributaries, where 

 it often reaches a height of one hundred feet and more, with a 

 diameter of six or seven feet. Professor Macoun states that 

 this tree in habit differs very much from the aspen, but in its 

 range it extends even farther north, and instead of being of 

 little value, as the aspen is, it attains a great size and height 

 as far north as the Arctic Circle on the Mackenzie River. West 

 of Manitoba and northward, it is usually found growing on al- 

 luvium in the river valleys, and in such situations it is often 

 nearly 150 feet high and frequently over 7 feet in diameter. 

 On the Peace River and all streams which unite to form the 

 Mackenzie, it occupies all the islands and low alluvial banks. 

 During the period of flood many trees fall into the rivers by 

 the wearing away of the banks, and a great number of them 

 in the course of time reach the Arctic Ocean. These are even- 

 tually cast on the islands and shores and become the chief source 

 from which is derived the fuel supply of arctic travellers. The 

 same may be said of the Yukon Valley, as it is this tree that 

 occupies the valley and islands of that river on all newly formed 

 lands, but in time gives place to spruce as the subsoil becomes 

 cold and moist from the density of the poplar and willow growth. 

 The Riviere aux Liards or Liard River (often erroneously called 

 Laird River), a tributary of the Mackenzie, is named from this 

 tree. 



The leaves differ from those of the poplars previously men- 

 tioned, by being narrower in proportion to their length. They 

 are ovate-lanceolate, acute or acuminate, dark green and lustr- 

 ous on the upper surface, pale and often ferruginous on the 

 lower. The usually broadened base is rounded or cordate. 

 The color of the bark is chestnut brown. The aments or catkins 

 appear in early spring, before the leaves, and the seeds are dis- 

 tributed about the end of May or early in June, covering the 

 ground with their snow-white cottony envelope. The w-ood is 

 light, soft and close-grained, but is not strong. The heart 

 wood is light brown and the sapwood white. Its specific gra- 

 vity is 0.3635, a cubic foot weighing 22.65 lbs. The leaf buds 

 are saturated with a yellow, balsamic, sticky exudation, which 

 gives the tree its specific name. 



