SYLVICULTUKAL NOTES ON POPLAR. 277 



b. Wliite Poplar. 



Europe, North Africa, North and West Asia, N. W. 

 Himalayas. Indigenous in Great Britain and Ireland. 

 Timber light, soft, specific gravity = '48 ; used for simi- 

 lar purposes as that of Aspen, but more valued. 



Found in low lands and river valleys, likes deep 

 loose moist soil, more exacting than Aspen. Growth 

 quick, stem straight; is light-demanding, foliage some- 

 what denser than that of Aspen. Eeproductive power 

 good, especially root-suckers. 



Best propagated by root-suckers, less well by cut- 

 tings. Treated as pollards, less suited for coppice. 

 Occasionally standards in coppice. 



c. Black Poplar. 



Europe, North Asia ; not indigenous in Britain, but 

 planted. 



Timber light, soft ; specific gravity = *45 ; most 

 valued next to that of White Poplar, and used for similar 

 purposes. 



Appears in low lands and river valleys. Thrives on 

 any soil, if loose and moist ; does not like heavy soils. 

 Grows rapidly, developing a straight stem, light-demand- 

 ing, hardy. 



Eeproductive power good by stool-shoots and root- 

 suckers. Best propagated by cuttings of various length. 

 Treated as pollards, sometimes standards in coppice. 



Insects injurious to Poplars generally : 



The leaves of young Poplars of all species are much 

 devoured by larveB, which are not gregarious, except 



