206 MANUAL OF TREE DISEASES 



The pores in the under surface are minute and the tubes 

 very short. 



Cause. 



The brown pocket-rot of conifers is caused by the fungus 

 Fomes roseus (formerly called Polyporus carneus Xees). The 

 fruiting-bodies described above are perennial and are formed 

 from dead areas on living trees or on the dead trees after they 

 fall. Infection seems to take place mostly near the base of the 

 tree and the rot is confined to the lower part of the trimk. The 

 wood is destroyed in the pockets by the extraction of the cellu- 

 lose. The lignin remains and the fibers retain their entirety, 

 although the walls are much thinner than normal. For a fuller 

 description of the life history and control of wood-rotting fungi, 

 see page 64. 



References 



Schrenk, Hermann von. Red rot, or pecky cedar (Polyporus eameus). 



In Two diseases of red cedar, caused by Polyporus juniperinus 



n. sp. and Polyporus carneus Nees. U. S. Dept. Agr. Div. Veg. 



Phys. and Path. Bui. 21 : 16-20, pis. 5-7, fig. 3. 1900. 

 Hedgeock, G. G. Notes on some diseases of trees in our national 



forests. IV. Phytopathology 4 : 181-188. 1914. 



White Pocket Heaetwood-Rot 

 Caused by Fomes juniperinus Schrenk 



Junipers are affected by this destructive heartwood-rot in 

 central United States. At times, the trees are made hollow 

 for several feet up and down the trunk. Trees more than 

 twenty-five years old are more often attacked than younger 

 individuals. 



Symptoms. 



Varying with the stage to which the decay has progressed, the 

 affected trees show one or more large holes at the center or are 



