Graves: Diseases of Trees in New York 119 



2. Inonotus hirsutus (Scop.) Murr. — The rusty brown or 

 chestnut colored, hairy surface of the pileus of this species, also 

 commonly known as Polypoms hispidus Fr., distinguishes it from 

 the nearly related species with a glabrous pileus, /. dryophilus 

 (Berk.) Murr., which is the agent of a very destructive heart rot 

 of oaks in the United States.^* With age the rusty brown color 

 may take on a black, carbonaceous hue, but usually some portion 

 of the pileus still has a ferruginous cast. Moreover, old speci- 

 mens often lose their dense covering of matted hairs, but are still 

 quite roughened. 



A tree of black oak {Quercus vehitina Lam.) in a forest on 

 Staten Island was found badly diseased, evidently through the 

 action of this fungus. Commencing about lo feet from the base 

 of the tree were several elongated cankers extending upward for 

 about 8 feet on the trunk and bearing fruiting bodies of the 

 fungus on exposed diseased wood. The trunk was considerably 

 hypertrophied in the region of the cankers, which were fairly 

 close together, and thus a long, spindle-shaped swelling in the 

 bole was formed — a condition which indicated the destruction' of 

 the inner wood by the fungus, and an attempted compensation for 

 this by increased growth of the sapwood. 



Dr. Murrill says that the species is rare in this country, but 

 common and virulent in Europe and very destructive to shade 

 trees there. The writer collected it on living European ash 

 (Fraxinus excelsior L.) near Torquay, Devon, England, in 

 1915, and also observed it on the same host in 1914 near Rugby, 

 Warwick. According to Prillieux^^ the parasite is not uncommon 

 on mulberry trunks in France. The same investigator and Dela- 

 croix record it among the enemies of the English walnut {Juglans 

 regia L.) in France. Butler^^ states that it is destructive to 



14 Hedgcock, G. G. Notes on some diseases of trees in our national for- 

 ests. II. Phytopath. 2: 73, 74. 1912. 



15 Prillieux, E. Maladies des plantes agricoles i : 352. 1895. 



16 Prillieux, E., and Delacroix, G. Les maladies des noyers en France, 

 Bui. de I'agricult. 1898: 1-14. Ref. in Just's Bot. Jahresb. 26^: ^77. 1898. 



17 Butler, E. J. Mulberry diseases. Mem. Dept. Agr. India. Bot. Sen 2^ : 

 1-18. 



The writer has been able to find no reference to this fungus as a pathogen 

 in the United States. 



