DISEASES OF SHADE AXD FOREST TREES. Ill 



radially, causing the wood to become soft and 

 yellowish or brownish in color. The sporo- 

 phon-s are large and shelving and usually al- 

 ums t twice as wide laterally as from front to back. The 

 pr< ])('! care of wounds will help to control the disease but it 

 i- frequently distributed by the locust borer. (See page 83.) 

 Tin- disused parts should be removed and destroyed and the 

 wounds treated. 



/'. juniperinus Schrenk attacks old red cedar trees caus- 

 ing a white heart rot. The fungus probably gains extrance 

 to tin- tree through dead branches which are most common in 

 old trees. The wood gradually loses its color, becomes 

 whitish and eventually undergoes disintegration leaving 

 holes through the center of branches and trunk. Fruiting 

 bodies are seldom formed. The removal of dead branches 

 and diseased parts will reduce the possibility of infection. 

 P. cameus ".Xees. also causes a white heart rot of both the 

 red cedar and arborvitae. It has been reported in this 

 State as occurring on dead logs but no doubt is Heart rots 

 aUn parasitic. The disease is characterized by and C arbOT- r 

 the formation of pockets or holes containing vitse - 

 more or less brown charcoal-like rotten wood. In advanced 

 suites these holes frequently unite. It should be treated the 

 same as the preceding. 



P. obtusus Berk, causes a soft heart rot of certain species 

 of the oak but is not of such great importance here as farther 

 wi >t. It is readily distributed by the oak borer (Prionoxys- 

 ///x rol'initi' Peck). It spreads rapidly up and 

 down the trunk and branches causing the heart * t ltheart 

 wood to become soft, white and brittle and very 

 easily broken in slight storms. The sporophores are hoof- 

 shaped, almost white when young, but changing with age to 

 a light brown. 



P. fraxinophilus Pk. is the cause of an im- ^ h 

 portaiit disease of the white ash in the Middle 

 West. It occurs as far east as Albany, Xew York, but has 

 not been reported from New Jersey. 



P. squamosus (Huds) Fr. is not common and is known 



