66 TREES AND SHRUBS 



POPLARS 



First among Poplars to bear its flowers, and 

 almost before winter is past, is the Aspen (Populus 

 tremula). This and its weeping variety bear their 

 catkins in February, but closely following it, and 

 perhaps more ornamental, is the American Aspen 

 (P. tremuloides). This species flowers early in March 

 near London in mild seasons, but later further north, 

 and when kept back by severe weather. The pendu- 

 lous variety of P. tremuloides known commonly as 

 Parasol de St. Julien is, at the flowering time, 

 probably the most beautiful and striking of all 

 catkin-bearing trees. This and also the type pro- 

 duce long, slender catkins that sway gently in the 

 softest winds. The weeping variety, which has 

 branches that weep naturally low, looks well by 

 itself on a lawn. In all these Poplars the male 

 catkins are three inches to four inches long, chiefly 

 grey-brown in colour ; the scale-like bracts, however, 

 are suffused with a reddish shade. The weeping 

 varieties of these two Aspens are frequently grafted 

 on the White Poplar, which is not a suitable stock. 

 The species to which the varieties severally belong 

 should be used for the purpose. It would be even 

 better if they could be got on their own roots by 

 means of layers or cuttings, and trained up to the 

 required height before allowing the weeping habit 

 to develop. 



There are others Poplars that bear their catkins 

 freely, such as P. alba, nigra, and balsamifera, but 



