108 MANUAL OF TREE DISEASES 



Uniform White Sapwood-Rot 



Caused by Hydnum septentrionale Fries 



This sapwood-rot is sometimes found in beech and maple. 

 The affected wood is white, soft and uniformly rotted. Brown 

 zones border the decayed area. \ Sometimes single and double 

 black lines are irregularly distributed in the white rotted wood. 

 Large, heavy, fleshy fruiting-bodies are formed on the side of 

 the tree. A thick sheet of mycelium grows over the bark and 

 from this project numerous small brackets with the imder sur- 

 face covered with teeth. The entire structure is white or yel- 

 lowish. For further details concerning this sapwood-rot, see 

 under maple diseases, page 234. 



White Butt-Rot 



Caused by Fames applanatiis Pries 



The heartwood of the roots and base of the trunk of beech is 

 occasionally destroyed by this rot. The decayed wood becomes 

 a little lighter in color than the normal wood. It is solid and 

 when split longitudinally numerous sinuous whitish tunnels are 

 apparent (Fig. 12). The decayed area is bordered by a broad 

 discolored zone. The sporophores of the causal fungus are 

 woody shelf-like bodies with a brownish or gray, smooth upper 

 surface and a white imder surface. For further details concern- 

 ing this wood-rot, see under poplar diseases, on page 310. 



Parasitized Roots 



Caused by Epiphegus virginiana Barton 



The roots of beech are parasitized by a peculiar flowering 

 plant, beech-drop {Epiphegus mrginiana). This plant belongs 

 to the family Orobanchacese, which comprises about one hun- 

 dred and fifty species, all of which are parasitic on roots of other 



