122 



Mycologia 



VII. Blight of Sycamore (Platanus occidentalis L.) 



The blight of sycamore, caused by Gnomonia veneta (Sacc. & 

 Speg.) Kleb. was seen in many places: practically no sycamore 

 was free from it. The fungus appears to be a slow parasite, 

 growing more especially during the early spring months during 

 the period of dormancy of the host. When observed during the 

 summer, the fungus' had in all cases apparently ceased its growth, 

 after killing terminal twigs here and there. This habit is prob- 

 ably largely responsible for the scraggly appearance of our 

 sycamore trees. 



Vni. Heart Rot of Locust (Robinia pseiidacacia L.) 



The black locust is very common in the area under considera- 

 tion, especially on Long Island. Its worst fungous enemy is 

 Pyro poly poms Robiniae Murrill, which attacks the heart-wood.-^ 

 The fruiting bodies are large, hoof-shaped structures, and are 

 of common occurrence but do not attract attention because they 

 are dark colored and usually high up on the trunk. 



During the summer the depredations caused by the locust leaf 

 miner (Chalepis dorsalis Thunb.) were conspicuous. 



IX. Injury from the Winter Conditions of 1917-18 



In an account of the most important and interesting patholog- 

 ical features Of the trees in the New York region, the effects of 

 the severe winter of 191 7-18 should by no means be omitted. It 

 is entirely unnecessary for the writer to establish the fact that 

 the winter was unprecedented, for that was perfectly clear to 

 all at the time. What he would like to emphasize is that the 

 combination or the chain of meteorological phenomena, aside 

 from the mere fact of the extreme cold itself, was especially 

 unfavorable for plant life. This cannot be better set forth than 

 by quoting from Dr. Taylor. After remarking on the extremely 

 low temperatures toward the latter part of December, he con- 



22 Schrenk, H. von. A disease of the black locust. Mo. Bot. Card. Rept. 

 12: 21-31. 1901. 



23 Taylor, N. Effects of the severe winter on the woody plants in the 

 garden. Brooklyn Botanic Card. Record 7: 83-87. 1918. 



