316 



Mycologia 



nns, C. Chantarellus, C. infundihuliformis, Hydrocybe conica, 

 Melanoleuca alhissima, Clitocyhe clavipes, Gymnopus carnosus^ 

 Lactaria torminosa, Cortinarius alhoviolaceus, Tyromyces lac- 

 teiis, Tremellodon gelatinosum, Hydnum velutinum, Helvella 

 crispa, Macropodia fusicarpa, Aleuria aiirantia, Otidea grandis, 

 and many other species. 



An old English walnut tree in Lynchburg, Vfrginia, was re- 

 ferred to in the last number Mycologia as having borne dis- 

 eased fruits since about 191 5. This walnut blight, Bacterium 

 juglandis, has been known since 1900 on the Pacific coast, where 

 it is considered a most serious disease and one not amenable to 

 treatment. In 191 3, it was reported in New York and New Jer- 

 sey, and in 191 6 it was found quite generally distributed in the 

 eastern United States. During the latter year, it was observed 

 that infection took place about the last of May, but the disease 

 did not penetrate deeply into the tissues of the nuts until the 

 middle of August. In California, infection occurs about flowering 

 time and is serious if the weather is moist. The only hope of 

 controlling this bacterial blight lies in the discovery of immune or 

 resistant varieties. 



The oldest Japanese chestnut tree on our grounds, one that has 

 survived since the early days of the Garden, persisting through 

 the terrible epidemic of canker which killed off all the other chest- 

 nuts, failed to put forth its leaves last spring. It is dead — killed 

 by an attack of the canker that was almost imperceptible at first 

 but finally proved too strong for it. This tree has been carefully 

 observed for fourteen years, or since the canker was discovered 

 in this vicinity. The disease gained entrance several years ago 

 through a small branch three feet above the ground and worked 

 away at the base of the trunk until it was completely girdled. 

 Only one small canker was found in the top of the tree, which 

 had a spread of twenty feet or more and remained green through 

 the season of 1918. 



Leaf-blight of the plane-tree and white oak has been unusually 

 prevalent this season, owing to the wet weather in May. This 



