122 ABSTEACTS: PHYTOPATHOLOGY 



error in assigning to Polyporus dryadeus, the rot produced by P. dryophi- 

 lus. Several synonyms for P. dryophilus are also given and the rot 

 produced by it compared to the rot produced by P. dryadeus. The 

 disease was found in the forests of Arkansas, Texas, Oklahoma, Mary- 

 land, and Virginia. The first evidence of the disease is a reddish brown 

 discoloration of the inner bark and cambium; in the final stage of the 

 rot the color becomes white or creamy white. In all the uprooted 

 trees examined, the disease began in the lower portion of the roots and 

 spread upward toward the stool of the tree. The rot was found in the 

 roots of Quercus texana, Q. nigra, Q. alba, Q. velutina, Q. minor, Q. 

 rubra, and Q. prinus. The following conclusions are presented : . 



1. Polyporus dryadeus is a root parasite of the oak producing a white 

 sap rot and heart rot in the roots. 



2. In all the trees examined this rot did not extend upward into the 

 tree as a true heart or sap rot of the trunk, but was limited to the under- 

 ground parts of the tree. 



3. The rot and sporophore described and figured by Robert Hartig 

 do not belong to Polyporus dryadeus but to P. dryophilus. 



4. In the majority of cases only old or much suppressed trees or 

 trees growing under very unfavorable conditions are attacked by this 

 disease. 



5. The disease does not seem to spread readily to adjacent trees. 



6. The disease is widely distributed Ijoth in America and Europe 

 and is probably found in these countries throughout the range of the 

 oak. W. H. L. 



PHYTOPATHOLOGY. — A71 underscribed species of Gymnosporangimn 

 from Japan. W. H. Long. Journal of Agricultural Research 

 1: 853-356. 1914. 



Attention is called to the introduction into this country of a new 

 species of Gymnosporangium on Juniperus chinensis from Japan. The 

 three types of teliospores in the genus Gymnosporangium which have 

 characters of specific value are described. 



Taxonomic descriptions are given of three species, Gymnosporangium 

 chinense, G. japonicum and G. haraeanum, all from Japan and on the 

 same host, Juniperus chinensis. The value of taking into considera- 

 tion at least two of the types of teliospores, the thin and thick-walled 

 ones found in each species of Gymnosporangium, is shown. W. H. L. 



