The Poplars 167 



spread of branches. This may be the tree referred to by 

 Macoun under the name of populus monilif era when he says : 

 "At Big Stick Lake, north of the Cypress Hills, there was a 

 grove of these trees of a very large size in existence in 1880. 

 These had escaped the annual prairie fires, being surrounded 

 and partly covered up by sand, and stood as a proof of the 

 existence of forests in the past, where now there is not even a 

 bush. The trees were over fifty feet high, and some of them 

 at least two feet in diameter." 



Britton gives its range from Saskatchewan and Alberta to 

 South Dakota, Nebraska, Kansas and Colorado. 



This is the cottonwood of the Western States, and it has been 

 largely used there for planting. The ranges of this and the 

 preceding species seem to meet in Alberta and Saskatchewan, 

 and their identity is not clear where they mingle. Usually 

 the term "cottonwood," without any qualifying word, means 

 either of these two trees. 



SILVER-LEAVED POPLAR. Populus alba. Linnaeus. 



The white poplar of Europe has been sparingly introduced 

 and is quite hardy throughout our range. It is easily recog- 

 nized by its slightly three or five-lobed leaves, which are rather 

 sinuately toothed and dark shining green above. The young 

 stems, the petioles and the under sides of the leaves are all 

 densely white-woolly. 



It grows rapidly, produces a good foliage and is easily prop- 

 agated from cuttings, but has the disadvantage of sending up 

 numerous shoots from the roots. 



RUSSIAN POPLAR 



Under this name a number of Asiatic species have been intro- 

 duced for ornamental planting. There are at least three species, 

 populus petrovski, populus certinensis and populus wobstiriga, 



