110 



SHADE TKEES. 



shelving sporophores or fruiting bodies (Fig. 41) frequently 

 overlapping. \Yhen young the upper surfaces are a bright 

 orange-red with a brighter red rim, very moist, and turn 



Fig. 41. Polyporus sulfureus on red oak. (Photo by 

 Dr. W. A. Murrill, N. Y. Botanic Garden.) 



brown when bruised. When mature they are hard, dry, 

 Fruiting brittle and sulphur colored. They are usually 



bodies. destroyed very early by insects. The treat- 



ment is the same as for the white heart rot. 



P. robinicB * Murrill attacks the black locust through 

 wounds and completely destroys the heart wood of living 

 trees. The rot begins at the center of the heart and spreads 



*P. robinice Murrill = P. rimosus Berkeley. 



