8 BULLETIN 89, U. S. DEPARTMENT OF AGRICULTURE. 



The chestnut over this area originated mainly from seedlings, and, 

 judging from the large annual increment, it made a healthy and 

 rigorous growth before this trouble appeared. 



NUMBER AND CONDITION OF THE INDIVIDUAL TREES EXAMINED. 



The roots of 71 dead or badly diseased trees were examined. Of 

 this number, 64 were chestnuts, 5 black oaks, 1 a chestnut oak, and 1 

 a sassafras. Of the chestnuts, 55 were already dead and 23 of them 

 had been blown down when the studies were made. This afforded 

 an opportunity to examine the condition of the roots. Nine of the 

 living chestnuts studied were either dying or badly stag headed. 

 Chestnut trees of all sizes were found dead or dying. Of the 64 

 chestnuts studied, 7 ranged in diameter from 4 to 10 inches, 23 from 

 11 to 20 inches, 29 from 21 to 30 inches, and 5 had diameters greater 

 than 30 inches. An occasional black oak was found dead or badly 

 stag headed, especially when adjacent to the worst affected chestnuts. 

 The chestnut oaks, however, seemed to be vigorous and in the best 

 of health. Especially valuable data were obtained from a wind- 

 thrown chestnut 38 inches in diameter, which had been living but 

 was badly stag headed when blown down . This tree was blown down 

 only 11 days before the data were taken. The condition of its roots 

 and stool was, therefore, exactly the same as when alive. When this 

 tree was overthrown, several of the most superficial roots were still 

 alive, but all of the deeper roots were dead. The sap wood of the 

 dead roots was white rotted and covered with a network of black 

 rhizomorphic strands. This rot was gradually encroaching on the 

 living roots and killing them. The tree stood on the top of a rocky 

 red-clay ridge, with the bulk of its roots within 2 feet of the surface 

 of the soil. 



All of the 71 trees examined had the "shoe strings" of Armillaria 

 mellea on their roots. They were also found in a few instances ex- 

 tending from 3 to 8 feet upward beneath the bark on both living and 

 dead trees. As a rule, however, the rhizomorphs were inconspicuous 

 and were confined mainly to the roots and stools of the affected trees. 

 The area studied was very limited, and no attempt was made to 

 examine the roots of a large number of living trees. The data given 

 here are therefore too meager to justify any positive opinion as to the 

 amount of damage done by this root-rot in North Carolina. How- 

 ever, the prevalence and apparent destructiveness of this fungus over 

 the area examined seem to point to it as very probably an important 

 factor in the gradual recession of the chestnut in that State. If such 

 an organism is at work, it would in a large measure explain the 

 hitherto unexplained phenomena associated with this recession, 

 such as the lack of reproduction from sprouts and the failure of the 

 chestnut to reoccupy its former territory. A more extended investi- 



