CHAP. XI,] 



SALICACE^. 



185 



and by the male flowers never having less than 

 eight stamens. The leaf-buds are also covered 

 with numerous scales. Fig. 82, a, shows the 



Fig. 82 — Trembling Poplar or Aspkn (Popuhts tremula). 



stamens of the Trembling Poplar or Aspen 

 {Popidus tremula) shrouded in their cup-like 

 calyx, and with their laciniated bract ; h shows 

 the female flower with its four stigmas and 

 deeply-cut bract ; and c, the pod with its valves 

 curling back, so as to show the downy covering 

 of the seeds. All these parts are magnified to 

 show them distinctly, as they are nearly the 

 same in all the species. The following are the 

 distinctions between the principal species. In 

 the White Poplar, or Abele-tree (P. alha)^ the 

 leaves are lobed, and covered with a white down 

 on the under side. In P. canescens^ the Grey 



