202 MASS. EXPERIMENT STATION BULLETIN 170. 



cases the top of the tree fails to produce foliage, and the characteristic 

 staghead effect is seen. (See Fig. 82.) We have observed elm trees 4 

 feet in diameter die suddenly from winter injuries to the roots, but more 

 often death from root injury in elms is a rather slow process, the branches 

 dying at the top and usually presenting the characteristic staghead 

 appearance. 



Elms and black oaks often show the results of root injury by tufted 

 foliage effects, especially when much of the upper part of the tree is 



Fig. 



73. — Elm branch with tufted foliage, resulting from wintefkilling. 

 A large percentage of the branches on this tree are dead. 



dead^ The few remaining live branches produce numerous large leaves, 

 — the result of an unbalanced relationship between the root system and 

 the upper portions of the tree. In all cases of root injury' those portions 

 of the tree farthest away from the water supply, or, more properly, those 

 wliich are in less direct communication with the main or principal chan- 

 nels of translocation or mobihzation, are affected first. In trees naturall}' 

 developing single leaders, such as the rock maple, the tops die back' first, 

 whereas in the elm, which has several leaders or branches located more or 



