BLACK POPLAR. 



629 



SPECIES OF POPLARS. 



GENERAL DESCRIPTION. 



HERE are three distinct species of Poplar, namely, the 

 Black Poplar (Populus Nigra), the White Poplar (Populus 

 Alba), and the Aspen (Populus Tremula). In addition 

 to these there are four varieties, namely, the Lombardy 

 Poplar (Populus Fastigiata), the Balsam Poplar (Populus Balsamifera), 

 the Black Italian Poplar (Populus Monilifera), and the Grey Poplar 

 (Populus Canescens). Of these, the Lombardy Poplar is a variety of 

 the Black Poplar, which it resembles closely in the construction of 

 buds, leaves, and catkins, though its branch formation is entirely 

 different, and the tapering column of its outline bears no likeness to 

 the full-spreading shape of the other tree. 



The Balsam Poplar is also a variety of the Black Poplar. The 

 stronger scent of its young leaves and buds, and the generally stiff 

 character of the tree, are its chief points of distinction. 



The Black Italian Poplar is yet another variety of the same 

 species ; it has a less spreading form, and an even more rapid habit 

 of growth. 



The Grey Poplar is either a variety of the White, or a cross 

 between it and the Aspen : in its general construction it resembles 

 both trees. 



All these species of Poplar, and their varieties, have certain 

 characteristics in common : they bear their leaves on long more or 

 less flattened stalks, which are set at right angles to the plane of 

 the leaf-blade. The individual tree bears either male or female catkins, 

 hut not both, and the catkins are very much like those of the Willow 

 in construction. All the Poplars grow with extreme rapidity. 



