А TRUNK DISEASE OF THE LILAC 
HERMANN VON SCHRENK 
Pathologist to the Missouri Botanical Garden 
A general discussion of diseases of the common lilac (Syringa 
vulgaris L.) was recently published by Klebahn (3). This 
author enumerates a number of diseases, such as the one of 
bacterial origin ascribed to Pseudomonas Syringe, various leaf 
diseases due to species of Microsphera, Gleosporium, and other 
leaf parasites, and a disease due to Botrytis cinerea. The 
major part of the work, however, deals with a disease due to 
Heterosporium Syringe Oud., affecting the leaves, and a serious 
twig blight due to Phytophthora Syringe Klebahn. Subsequent 
papers by various writers deal with one or the other of the 
diseases mentioned by Klebahn. 
During recent years а destructive trunk disease of the com- 
mon lilac (Syringa vulgaris L.) has been noted a number of 
times in the Missouri Botanical Garden, and in grounds in the 
vicinity of St. Louis. The affected plants were usually old 
bushes which had been more or less neglected, and the tops of 
the leading trunks were frequently dead. Long shoots from the 
root and others from the part of the trunks near the ground made 
a dense tangle around the main stem; on the latter sporophores 
of Polyporus versicolor were found in various stages of develop- 
ment, sometimes isolated, but more frequently in groups. Sec- 
tions were made of the trunks on which this fungus was growing 
and it was found that such trunks were invariably diseased, 
while those close by, either from the same root system or from 
adjacent bushes—which were free from the fungus—were al- 
ways sound. 
In pl. 8 fig. 1 two affected trunks are shown cut at points 
about three feet from the ground. In both cases the larger 
part of the stem was alive, as evidenced by the presence of 
vigorous shoots along the entire length. РІ. 8 fig. 2, and pl. 
9 figs. 1, 2 represent sections of lilac trunks taken from different 
bushes to show different stages of the disease. 
Ann. Мо. Вот. GARD., Vou. 1, 1914 (253) 
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