UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 759 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
June 19, 1919 
THE LEAF-SPOT DISEASES OF ALFALFA AND 
RED CLOVER CAUSED BY THE FUNGI PSEU- 
DOPEZIZA MEDICAGINIS AND PSEUDOPEZIZA 
TRIFOLII, RESPECTIVELY 
By 
FRED REUEL JONES, Pathologist, Cotton, Truck, and 
Forage Crop Disease Investigations 
CONTENTS 
Page 
Scope of the Investigation 1 
The Diseases *S 2 
Economic Importance • . „....' 2 
Description of the Disease on Alfalfa 3 
Description of the Disease on Red 
Clover 4 
Host Plants 5 
The Fungi „ 5 
Synonomy of Pseudopeziza trifolii . 5 
Synonomy of Pseudopeziza medi- 
caginis 6 
Comparative Morphology of the Fungi 6 
Morphological Characters in Culture 8 
Page 
The Fungi— Continued. 
Reported Conidial Stages of These 
Fungi . . o . 9 
Physiology of the Fungi ..... 11 
Pathogenicity of the Fungi .... 19 
Life History of the Causal Organism in 
Relation to the Host Plants .... 27 
American Studies Bearing on Life 
History". 27 
Method of Overwintering .... 28 
Method of Distribution 30 
Summary . . . „ 35 
Literature Cited 36 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1919 
