54 i 1 1 1 NESE ECONOMIC TREES 



North China. 



Useful for a quick-growing windbreak. On young sprouts the leave? 

 ;ire broadly elliptical, 7-16 cm. long. 



Populus lasiocarpa Oliver. 



Tree 13 m. high with dark gray fissured bark and pyramidal or 

 rounded crown. Branchlets pubescent, angled. Leaves very large, some- 

 times 30 cm. long and 17 cm. wide, deeply cordate at the base, acuminate 

 and gland-tipped at the apex, regularly and glandularly serrate; upper 

 surface with a dense, white, pubescent tuft at the base, glabrescent with 

 age; lower surface more or less tomentose, midribs and veins reddish; 

 petioles red, round. Staminate catkins 10 cm. long. Capsules 2-3 valved, 

 densely tomentose. 



North China. 



Dr. Henry states that this is a good timber tree. 



Populus tomentosa Carriere 



Tree 25 m. tall with gray tomentose branchlets and triangular, ovate 

 leaves; margin with 10 or less sinuate teeth on each side. 



North and Central China. 



Large specimens are growing on the grounds of the Summer Palace 

 in Peking. This is one of the best and largest poplars. The leaves 

 are large. 



1 o v 



Populus tremula Linn, var Davidiana Schneider. 

 Trembling Aspen. 



Medium sized tree up to 20 m. tall at best, producing suckers freely. 

 Young leaves reddish-purple, conspicuous at the time of unfolding. 

 Leaves thin, small, ovate, margin with rounded, incurved teeth; petioles 

 long, slender, laterally flattened. Scales hairy; stigma deeply cleft; 

 stamens 6-8. 



This variety is the Chinese representative of the common European 

 Aspen. Several horticultural forms are cultivated, notably a weeping 

 and a tomentose form. 



E. Asia and China. 



