36 FAMILIAR TREES 



their female catkins lax, their scales almost smooth, 

 and their stamens more than twelve in number ; and 

 they have been accordingly united in the section 

 named Aigei'ros a name formerly applied to the 

 Black Poplar. It will, perhaps, be clearer to give 

 their characters in succinct form. 



Populus. Section I. : Leuce. Shoots downy ; 

 female catkins dense ; scales ciliate ; stamens four 

 twelve. 



1. P. alba L., White Poplar, or Abele : Leaves on 

 the suckers lobed, those on the branches roundly 

 heart-shaped, slightly lobed ; white and cottony on 

 the under surface; stigmas two, bifid, linear, cross- 

 like, yellow. 



2. P. canes'cens Sm., Grey Poplar : Leaves on the 

 suckers angled and toothed, those on the branches 

 roundly heart-shaped, hoary or smooth on the under 

 surface ; stigmas two-, three-, or four-lobed, wedge- 

 shaped, purple ; buds downy. 



3. P. trem'ula L v Aspen: Leaves on very long stalks, 

 those on the suckers heart-shaped, pointed, not 

 toothed, those on the branches rounded, with incurved 

 teeth, silky or smooth on the under surface ; stigmas 

 two, bifid, erect ; buds slightly viscid. 



Section II : Aigeiros. Shoots smooth ; female 

 catkins lax ; scales nearly smooth ; stamens twelve 

 twenty. 



4. P. nigra L.. Black Poplar: Leaves on long stalks, 

 when young rhombic in form, silky on the under 

 surface, and ciliate; when old more rounded finely 

 toothed, smooth ; stigmas two, roundish, two-lobed ; 

 buds viscid ; no suckers. 



