THE STERILE FUNGUS RHIZOCTONIA AS A 
CAUSE OF PLANT DISEASES IN AMERICA. 
Being a PRELIMINARY Report UPON THE OCCURRENCE OF DISEASES 
| oF PLANTS IN AMERICA CAUSED BY DIFFERENT FORMS 
- OF THE STERILE FunGus RHIZOCTONIA. 
By B. M. Duaear, Cryptogamic Botanist, Cornell University Agl. Exp. 
Sta. and F. C. Stewart, Botanist, New York Agl. Exp. Sta. 
INTRODUCTION. 
Studies on a beet root-rot and a carnation stem-rot in 1898 
first drew the writers’ attention particularly to the fungus 
Rhizoctonia as a cause of various plant diseases in this country. 
It needed no extended search to ascertain that this fungus is 
much more commonly associated with diseases of certain green- 
house and field plants than our economic literature would sug- 
gest. During the three seasons that our attention has been 
directed to this matter, the occurrence of Rhizoctonia on some 
entirely new hosts has been observed, and also upon other hosts 
new to America. As a preliminary report, it now seems well 
to bring the subject to the attention of American mycologists. 
Our work is directed towards a monograph including all known 
species of this fungus; and it is hoped that these notes will 
enlist the support of other workers, and some contributions of 
material. 
Besides a brief historical and morphological account, this bul- 
letin concerns itself merely with the presentation of some notes 
upon the occurrence and destructiveness of American forms 
observed by the authors. We reserve for the final paper all 
details of special morphology and physiology of the forms, as 
well as general matters of taxonomic interest and a discussion of 
