VOLUME LItI NUMBER 3 
ey SS 
BOTANICAL (GAZETIE 
SEPTEMBER 1917 
A PRELIMINARY REPORT ON THE YEARLY ORIGIN 
AND DISSEMINATION OF PUCCINIA 
GRAMINIS 
FREDERICK J. PRITCHARD 
(WITH PLATE IV) 
Introduction 
The annual reappearance of Puccinia graminis Pers., the black 
rust of cereals, and its dissemination among the various species 
of the Gramineae, have long remained obstinate problems. For 
nearly a century botanists and also agronomists, because of its 
economic importance, have endeavored to discover how this 
fungus passes the winter and spreads to the grain fields. A review 
of the literature, to bring out certain points which have been too 
much overlooked by those who are committed to the conception 
that the barberry is the sole source of spring infection, will be of 
interest in connection with the data which my own observations 
afford. 
The barberry was considered a disseminator of rust by careful 
observers centuries ago. Even as early as 1660, as a result of 
their reports, an act of Parliament was passed at Rouen (22) con- 
demning the use of this shrub in the vicinity of grain fields. A 
similar law was passed in Mass. (28) in 1755. Successive measures 
of this nature were subsequently enacted throughout Europe (3). 
Proof of the influence of the barberry on rust contagion was 
furnished by ScHGLER (29), who in 1818 succeeded in infecting 
* Cited by ErrKsson. 
169 
