UNITED STATES DEPARTMENT OF AGRICULTURE 



^ BULLETIN No. 380 



Contribution from the Bureau of Plant Industry 

 WM. A. TAYLOR, Chief 



s\J^'^^u 



Washington, D. C. 



PROFESSIONAL PAPER 



January 15, 1917 



ENDOTHIA PARASITICA AND RELATED SPECIES. 



By C. L. Shear, Pathologist, and Neil E. Stevens/ Pathologist, Fruit-Disease 

 Investigations, and Ruby J. Tillee, Scientific Assistant, Office of Investiga- 

 tions in Forest Pathology. 



CONTENTS. 



Taxonomy 1 



Introduction 1 



Thegenus Endothia 3 



The species of Endothia 13 



Morphology and development 22 



Mycelium 22 



Stromata 23 



Spore measurements 30 



Physiology 36 



Cultural studies 36 



Physiology— Continued . 



Distribution of the species of Endothia. - 48 

 Discovery of Endothia parasitica in 



China 54 



Discovery of Endothia parasiticain Japan 58 

 Present distribution of Endothia para- 

 sitica in America 59 



Host relations of the species of Endothia . 59 



Summary 74 



Literature cited 77 



TAXONOMY. 



INTRODUCTION. 



The discovery of a serious canker of the chestnut in the New York 

 Zoological Park in 1904, by Merkel (49),^ first attracted the atten- 

 tion of pathologists and foresters to what has proved to be one of 

 the most serious epidemics of a plant disease ever known in this 

 country. 



The fungus which was found associated with these cankers (PL 

 I and PL II, fig, 1) and soon demonstrated experimentally to be 

 their cause was described by Murrill (57) in 1906 as a new species 

 of Diaporthe (D. parasitica) . Search for the fungus in other places 

 in New York and vicinity soon showed that it was already estab- 

 lished and apparently rapidly spreading. Investigations which 

 have been continued and extended from year to year have shown 



1 Formerly Pathologist, OfHce of Investigations in Forest Pathology. 



2 Serial numbers in parentheses refer to " Literature cited," at the end of the bulletin. 



Note. — This bulletin is of value to botanists, especially plant pathologists and mycolo- 

 gists, and to all persons who are interested in the study of chestnut blight. 

 43737°— Bull. 380—17 1 



