66 Native Trees of Canada 



It is not abundant in Canada, being confined in its distribution to the banks 

 of streams in southern Alberta, and is of no commercial value. In habit and dis- 

 tribution it is hke the narrowleaf cottonwood and is often mistaken for that tree. 



The bark on young trees is smooth and nearly white, on old trunks it is 

 greyish-brown and deeply cut into broad, flat ridges. 



The twigs are slightly four-angled in cross-section and roughened by projecting 

 leaf-scars. Their greenish-brown colour distinguishes them from the orange- 

 brown twigs of the narrowleaf cottonwood. 



The winter buds are longer, more curved, more resinous, and the points are 

 more drawn out than those of the narrowleaf cottonwood. 



The leaves are 2 to 4 in. long and ^ to 2 in. wide, and more coarsely notched 

 than those of the narrowleaf cottonwood. The base is tapered and the tip long 

 drawn out. They are dark green and shiny above and have a slender, yellow 

 midrib. 



POPULUS ANGUSTIFOLIA, James NARROWLEAF COTTONWOOD 



The narrowleaf cottonwood is a medium-sized tree, 35 to 40 ft. high and 12 

 to 18 in. in diameter, and with a narrow, pyramidal crown. Its wood is seldom used 

 commercially. 



Like the lanceleaf cottonwood it is confined to the banl^s of streams in southern 

 Alberta and Saskatchewan, and is often mistaken for it. These trees can be readily 

 distinguished by their leaves, those of the narrowleaf cottonwood being 2 to 3 in. 

 long, 3^ to 1 in. wide, narrow, tapering, and sharp-pointed. The leaf resembles 

 more the leaf of a broadleaf willow than that of a poplar. The base is rounder, the 

 notching is finer, and the stem is shorter than that of the lanceleaf cottonwood. 



POPULUS DELTOIDES, Marsh. COTTONWOOD 



Common names: Cottonwood, common cottonwood, eastern cotton- 

 wood. 

 French names: Liard, cotonnier, peuplier monalifere. 



The cottonwood is one of the largest of the poplars, averaging 75 to 100 ft. 

 in height and 2 to 4 ft. in diameter. 



The crown is conical and fairly dense on young trees, but spreads out and opens 

 up as they become older. 



On old trees the bark is dark grey and more broken than on most poplars. 



The tree can be distinguished from the other poplars in winter by the yellow- 

 ishness of the twigs and by the divergent buds. Ridges run down both sides of the 

 twig from the bases of the leaf-scars. Young sprouts are, also, often angled. 



The winter buds are glossy and resinous, but have less resin than most of the 

 poplars. They are J^ in. long, somewhat flattened, and chestnut-brown in colour. 



The leaves are a good distinguishing feature in summer. They are triangular 

 in outline and coarsely toothed. The base is square and the apex long and pointed. 

 The length and width are about the same. The stems are compressed sideways. 



