

116 



MISSOURI BOTANICAL GARDEN 



2, A tree 



Q 



The trunk is rotted throughout heart and sap wood. 



Plate 16. 



Q 



Poly poms obtnsus Berk. Only a small part of the heart wood is here 



affected. 



Q 



rotted heart wood with an insect burrow partially filled with the 

 mycelium of Polyporus obtnsus Berk. 



Plate 17. — Stem of Querent velutina split to show the insect burrow, 

 which is on the left side, running upward from the opening in the bark 

 midway the length of the block toward the center of the tree. To the 

 right and above the upper end of the burrow is seen the lighter colored 

 rotted heart wood. The burrow is filled with a mass of mycelium of the 

 fungus, Polyporus obtusus Berk. 



of a tree of Quercus marilandica with an insect 

 There is but a small area of white rotted wood 



Plate 18. 

 burrow on the right, 

 adjacent to the burrow. 



Plate 19. 



Q 



by the fungus. The insect burrow shows very plainly. The entire stem 

 was rotted except on the extreme left next to the bark, where a thin 

 darker layer of the sap wood is seen. 





1 \ 



M 



