442 CALIFORNIA ACADEMY OF SCIENCES. 



PucciNiA SUBCIRCINATA, E. & E., witli ^ciDiUM. — On liv- 

 ing leaves of Senecio triangularis, Donner, August^ 1883. 



3572 



PucciNiA YiOL^, DC., with ^cidium. — On living leaves of 

 Viola canina, Cisco, July — August, 1883. 3486, 3544 



PucciNiA Wyethije, Pk. — On living leaves of Wyethia mol- 

 lis, Donner, Sierra Nevada, September, 1882. 3406 



Peronospora viticola, B. & C. — On living leaves of Viti^ 

 Calif ornica, near Bartlett Springs, Lake County, June, 1884, 

 and Eussian Eiver, June, 1886. "^ 3706, 4128 



Tliis fungus, forming large white patches, is confined to 

 the lower surface of the leaf, where only the stomata from 

 which it emerges is found. The corresponding part of the 

 upper surface is much paler than the healthy portion of the 

 leaf, on which account it is noticeable to a considerable dis- 

 tance. In both the cases noted above it was very abundant, 

 and is a menace to our vineyards not to be lightly re- 

 garded. 



It was first observed in 1872, in a vineyard near Sacra- 

 mento, which has since, the vines having been uprooted, 

 been devoted to other uses. The vineyard was near the 

 levee and in close proximity to wild grapevines, from which 

 the fungus was undoubtedly derived. 



Dr. Farlow, in Bull. Bussey Inst. i. 422, March, 1876, 

 speaking of this disease of the vine, says: 



" One would naturally suppose that a fungus so common 

 as Peronospora viticola, which often is found on every leaf 

 of a vine, would have an injurious effect upon the grape 

 crop. Such, however, is not the case. The fungus does 

 not attack the grapes themselves; nor does it, at least in 

 New England, appear until about the first of August; and 

 its withering effect upon the leaves is not very evident be- 

 fore September. As far as out-of-door grape culture in the 

 Northern States is concerned, we are inclined to believe. 



