BRITISH FOREST TREES 293 



bright yellow, golden leaves contrast well with the darker 

 russet hues of the oak and beech. 



( Growth in high forest is suited for neither species, whilst 

 they are not remunerative enough, and do not attain 

 sufficiently good proportions, to make it worth while to 

 train them as standards in copse to take the place of trees 

 yielding better monetary returns. For arboreta, parks and 

 the residential portions of large estates, however, their culti- 

 vation deserves a fair amount of attention. 



B. Softwoods. 



i. THE WHITE ALDER (Betula alnus, L. =ALNUS INCANA, 



B.C.). 



Distribution. The white alder is distributed throughout 

 central and northern Europe, and the greater portion of 

 western and northern Asia and North America. It is 

 found at elevations up to 5,100 feet in the Tyrolese Alps, 

 4,500 feet in the Bavarian Alps, 2,300 feet in the Baienvald, 

 and 2,100 feet in the Erzgebirge. Its development, how- 

 ever, is incomplete at lofty elevations, and it is in reality 

 more a tree of the plains, and the lower hills and uplands, 

 than of the mountains. It nowhere forms extensive forests, 

 but occurs mostly in small pure clumps and patches, or, 

 when artificially formed, in combination with willows, horn- 

 beam, and other moisture-loving trees. 



Tree form and Root-system. It develops a straight 

 smooth stem with a moderately foliaged crown, which 

 rounds off and broadens as early as the fifteenth to 

 twentieth year, demanding thereafter increased growing- 

 space. Its growth in height therefore is not great. The 

 crown, borne by long, straight, elastic branches set at a 



