Graves: Diseases of Trees in New York 121 



Marsh, the paper birch, and other species of birch. Weir-*^ re- 

 cords it on Hving trunks of Populus trichocarpa Torr. & Gr., the 

 black Cottonwood, in Montana. 



The sporophores resemble closely those of Pyi'opolyporus 

 (Fomes) igniariits (L.) Murr., but the spores of the latter are 

 colorless, while those of this species are yellowish brown. An- 

 other distinctive feature seems to be the bright yellow color of 

 the mycelium of which the pileus -is composed. Dr. Murrill says 

 that he also has used this bright color as a field character. 



V. Disease of the White Oak {Querctts alba L.) 



All over Staten Island the white oaks of large size were found 

 to be dying out. This was not due to the severe winter preceding, 

 for Dr. Arthur Hollick, of the Staten Island Institute of Arts 

 and Sciences, informed the writer that the trouble has been going 

 on for several years. There was no patch of forest in which the 

 dying and dead trees could not be seen on every hand. Rhizo- 

 morphs (possibly of Armillaria mellca (Vahl.) Quelet) were 

 found under the bark of many, but not all trees. It seemed as if 

 the larger trees were the ones that were affected. In some in- 

 stances traces of a boring beetle were seen. 



VI. Bark Disease of the Paper Mulberry 



(Brottsso)ietia papyrifera Vent.) 



Near Bayside, L. I., a large paper mulberry about one foot in 

 diameter breast high, growing as a shade tree in a front yard, was 

 found badly diseased by Creonectria purpurea (L.) Seaver 

 {Nectria cinnaharina Fr.) at the base of the trunk. The poten- 

 tial pathogenicity of this species has been proven beyond ques- 

 tion,-^ and there was no doubt here that the fungus was advancing 

 in the living bark. And yet it is known to often lead a purely 

 saprophytic life on dead twigs. 



20 Weir, J. R. Montana forest tree fungi I. Polyporaceae. Mycologia 9 : 

 135- 1917- 



21 Mayr, H. Uber den Parasitismus von Nectria cinnabarina. Untersuch. 

 a. d. Forstb. Inst, zu Miinchen. III. 1882 



