Missouri Botanical 
Garden Bulletin 
Vol. Ill St. Louis, Mo., November, 1915 No. 11 
AN EXHIBIT OF THE CHESTNUT BARK DISEASE 
Among the various fungous diseases which are destructive 
to trees, perhaps the one which attacks the chestnut bark 
has attracted more attention in recent years than any other. 
While there are few chestnut trees growing in Missouri, the 
number of inquiries which have come to the Garden concern- 
ing the blight indicate that there is considerable local in- 
terest in it, and an exhibit illustrating the effect of the 
fungus has been installed in the Museum building. 
This disease of the chestnut was first discovered in New 
York in the year 1906. All the evidence at hand points to 
its having been introduced from the Orient with nursery 
stock about twenty-five years ago. From the vicinity of 
New York City it spread eastward and southward with an 
alarming rapidity, until at the present time the region in- 
fected extends from Maine on the north to North Carolina 
on the south. Not only has the spread of this disease been 
phenomenal, but it has literally swept everything before it, 
with the result that healthy chestnuts are now all but un- 
known in western Connecticut, southern New York, Dela- 
ware, New Jersey, and eastern Pennsylvania, and in the 
centers of worst infection every chestnut tree has been killed. 
The pest bids fair at the present time to wipe out completely 
the chestnut throughout its range along the Appalachian 
Mountains unless some successful method of attack should be 
found within a few years. 
The chestnut bark disease is due to the fungus, Endothia 
parasitica, which attacks exclusively the chestnut and the 
chinquapin. This fungus can enter the bark only through 
wounds of various sorts, such as are caused by mechanical 
injury, insect punctures, woodpecker holes, etc. Once the 
fungus has started in the bark or cambium, it progresses very 
steadily and rapidly, and although it remains practically 
- dormant during the winter months, growth is vigorously re- 
sumed with the return of warm weather. The cankers are 
produced on both the branches and the main trunk, and 
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