LIFE-HISTORY STUDIES IN SCLEROTINIA 
By F. J. SEAVER AND W. T. HORNE 
New York Botanical Garden University of California 
(WITH PLATE 3) 
For several years past a species of Sclerotinia has been observed 
by the writer in a certain stretch of woods in the upper end of Van 
Cortlandt Park, New York City, on the rootstocks of wild gera- 
nium. Although this has been seen abundantly in this particular 
region, it has not been detected by us in other localities where the 
wild geranium grows. The apothecia usually appear early in the 
spring about the latter part of April or early in May and disappear 
early in June. A search of the records showed no species of Sclero- 
tinia listed for this host, so that the writer was uncertain whether 
this represented an undescribed species or some old species on a 
new host. It did not appear, however, to agree well with any 
described species, and it was finally decided to publish it in order 
to bring it to the attention of mycologists. Before doing this it 
was thought advisable to locate the conidial stage, if possible, in 
order to make the description more complete, and during the spring 
of 1917 this work was undertaken. 
From our knowledge of other species of Sclerotinia, it was 
thought that the conidial stage might be located as a parasite on 
the leaves or other living tissue of the host. A careful search of 
the region in which the fungus occurred on various occasions 
showed nothing on the living plants which could be suspected of 
being the conidial stage of this fungus. A collection of infected 
rootstocks, however, which had been brought into the laboratory 
and placed in a moist chamber after a few days showed a most 
luxuriant growth of a species of Botrytis. This appeared in dense 
tufts not only on the rootstocks and rootlets, but even covered 
cver the outside of the apothecia like a coat of fur. While none of 
the Botrytis was apparent on the plants when brought into the 
laboratory. it invariably appeared within a few days on the roots 
202 
