176 



POPULUS. 



of these suppositions is the correct one, is not for us to 

 determine, and, indeed, the attempt to do so, with our 

 limited botanical knowledge, would be presumptuous. We 

 therefore only venture to suggest that, if they are only 

 varieties of one species, the original stock is more likely 

 to be the Pop. canescens than the Pop. alia, the first appear- 

 ing to have a wider geographical distribution, and to be 

 more generally met with in a wild and indigenous state, 

 than the latter. 



It is distinguished from the Pop. alba by its leaves, 

 which are less deeply and 

 acutely lobed, and, instead 

 of being covered with the 

 thick, snow-white down 

 which clothes the under 

 surface of the leaves of the 

 Abele, the downy substance 

 is sparing and of a grey 

 colour, and, indeed, in some 

 instances, the leaves are 

 almost glabrous. The catkins of the female Pop. canescens 

 also are cylindrical instead of oval, and the stigmas eight 

 instead of four. Other characters also are not wanting, 

 such as the growth of the branches, which are more up- 

 right and compact in Pop. canescens, whose bark is also 

 different in colour from that of Pop. alba. 



The Grey Poplar attains in favourable situations, such 

 as a loose moist soil on the banks of a river, pond, or like 

 locality, a very large size, frequently running up to the 

 height of eighty or ninety feet, with a diameter of trunk 

 from three to five, and even seven feet.* 



See statistics of this tree in the " Arboretum Britannicum. 



