344 MANUAL OF TREE DISEASES 



White Wood-Rot 

 Caused by Trametes suaveolens Fries 



Willows in eastern and central United States are commonly 

 affected by this white wood-rot. The disease seems to be most 

 destructive when willows are badly wounded by the breaking 

 of branches or by injudicious pruning. The actual importance 

 and symptoms of this wood-rot have apparently not been studied 

 as but little has been published on the disease. The sporophores 

 of the causal fungus are easily recognized. They are sessile, 

 annual, shelf-like bodies, usually foiu* or five inches broad, and 

 project three or four inches from the trunk. The upper sur- 

 face is convex, smooth, whitish or gray and velvety to the touch. 

 The under surface is flat, white or grayish and has a chamois-skin 

 texture. The pores on the under surface are large. This fungus 

 occurs only on willow and produces fruiting-bodies abundantly. 

 For a general discussion of the life history and control of wood- 

 rot fungi in living trees, see page 64. 



