THREE UNDESCRIBED HEART-ROTS OF HARDWOOD 
TREES, ESPECIALLY OF OAK 
By W. H. Long, 
Forest Pathologist , Investigations in Forest Pathology , Bureau of Plant Industry 
INTRODUCTION 
During an investigation made in 1912 of the pathological condition of 
the oaks in the Ozark National Forest, of Arkansas, and in other sections 
of the United States the writer found a large percentage of the trees, 
especially in some regions of Arkansas, attacked by various fungi which 
rot the heartwood. Twenty different kinds of heart-rots were found. 
Of this number eight have been previously described and assigned to 
their causative fungi; two were caused by well-known fungi, but no 
detailed specific descriptions of the rots have yet been published; one 
proved to be a true root-rot caused by Polyporus dryadeus; three 
have not yet been connected with their causative organisms; while six 
have been for the first time definitely associated by the writer with the 
fungi which produce them. Only three of these last six rots will be 
discussed in this paper. 
INVESTIGATIONS OF HEART-ROTTING FUNGI 
The writer found in the Ozark National Forest ideal conditions for the 
study of heart-rotting fungi, as thousands of white-oak trees (Quercus 
alba L.) were being worked into 36-inch staves for whisky barrels. Trees 
over 16 inches in diameter were felled and sawed into about 3-foot 
lengths; these were immediately split into what are known as bolts. 
As only perfectly sound timber can be used for whisky staves, all rotten, 
wormy, water-soaked, and stained pieces were rejected and left on the 
ground where the tree was cut. It was therefore very easy to determine 
the character and extent of the rot in each tree. As the areas being 
cut were in a virgin forest, all ages of trees down to about 160 years old 
(16 inches in diameter) were included. The majority of the trees were 
cut very close to the ground; the stumps averaged 12 inches in height, 
but in many cases were much lower. This aided in the investigation, 
since the nearer the ground the trees were cut the more complete was 
the record as to the rot in the trunks. 
Of the twenty rots found in oak, only the following eight were pres¬ 
ent to any extent in the trunks and tops of the trees: 
(1) A rot which produces hollows caused by Hydnum erinaceus; 
(2) a brown, checked rot caused by Polyporus sulphureus; (3) a 
(109) 
Journal of Agricultural Research. 
Dept, of Agriculture, Washington, D. C. 
Vol. I, No. a 
Nov. 10,1913 
G-a 
