Nov. io, 1913 
Heart-Rots of Hardwood Trees 
123 
tree compared to its radial rate of growth and the subsequent rather 
complete absorption of the entire heartwood in the stool of the tree 
produce a peculiar condition when the tree is cut. A tree in which this 
rot has reached its last stages in the stool will be rotted to or nearly to 
the sapwood for 1 to 3 feet from the ground, and such a tree will fall as 
soon as the thin shell of sound wood is severed, carrying with it the par¬ 
tially rotted heartwood, which easily pulls loose from the badly rotted 
mass in the stool. The butt end of the felled tree will then have attached 
to it a cylinder of rotted wood some 1 to 2 feet long in the string and 
ray stage, thereby leaving a hollow stump in the bottom of which there 
will be the wet, very rotten mass of wood held together by the threads 
of mycelium. 
This rot has a very strong but pleasant odor, somewhat like that of 
anise oil. This odor disappears after the exposure of the rot to the air 
for several weeks, but is so marked when the tree is first cut that it can 
be detected at a distance of from 20 to 30 feet. 
Studies were made of 1,938 white-oak trees which were cut for staves. 
Of these, 57 had this rot. The average diameter of the rot in these 57 
trees was 19 inches; the average height per tree was 3.5 feet; and the 
average age per tree was 280 years. The maximum diameter and height 
for this rot in any one tree were found in a tree 380 years old. The 
diameter of the rot was 32 inches and the height was 13 feet. As a rule, 
this rot does not extend very high in a tree, as compared to its extent in 
diameter, and ends very abruptly in perfectly sound wood. It was 
also found in the butts of two black oaks (Quercus velutina); the sporo- 
phores of the fungus were seen several times on the roots of both white 
and black oaks which had not been felled. The writer repeatedly found 
from one to three sporophores of Polyporus berkeleyi (PI. VIII, fig. 3) 
attached to the roots of the trees in which this characteristic heart-rot 
was present. The direct connection of the rot in the stump with the 
sporophore could easily be traced by following the rot down into the 
stool and thence through the rotted heartwood of the root to the 
sporophore. This was done in the case of at least a dozen trees. 
The youngest tree found with this rot was 170, the oldest 500 years 
of age. The rot was usually found in mature and overmature trees 
from 25 to 32 inches in diameter which grew in rich soil on north slopes. 
In 6 of the stumps of the 57 white oaks found affected with this rot some 
evidence as to the age of the rot was obtained. The oldest rot was 380 
years and was found in a tree 420 years of age. The average age of the 
rot in these six trees was 190 years. The average rate of growth of the 
rot was 1 foot in height and 5.4 inches in diameter for every 60 years 
of age. The fungus producing this rot usually enters the tree through 
some wound at the butt, such as fire scars. No evidence was found 
that it could enter through broken branches. In no instance was the 
