GEOGRAPHICAL DISTRIBUTION AND ECONOMIC 



IMPORTANCE. 



Cronartiiim ribicola occurs in several European countries, and 

 probably in India, but has never been found in Australia or in 

 South America and in North America but once. 



It was originally described in 1856 from specimens collected 

 in western Russia. Since that time it has been reported from 

 other places in Russia even to the Ural Mts. on the east and 

 to the Caucasus Mts. on the south. In Germany it is common 

 and the injury which it does to the white pine is of considerable 

 economic importance. Klebahn has reported a destructive out- 

 break of the disease among white pines in the vicinity of Bremen 

 in 1887. Tubeuf, in 1898, stated that specimens of it were to be 

 found all over Germany and that it was destructive in the north- 

 eastern part. Among other instances of severe damage he men- 

 tions a large nursery near the Holland border in which the culture 

 of white pines had been entirely given up on account of the fungus. 

 In another publication the same author stated that the disease was 

 spreading and becoming a serious menace in Germany. Eriksson 

 describes its epidemic occurrence in Sweden. Bos states that in 

 Holland it is so abundant that in many localities the culture of 

 white pines is impossible. It is also reported from Belgium, 

 Denmark, Norway, Switzerland, France, Austria and England. 



Judging from the European literature on the subject, it ap- 

 pears that as a currant disease Cronartiiim ribicola is regarded as 

 of little importance even in those regions in which it is abundant, 

 but as disease of white pines it has caused much damage. 



American mycologists, believing that it must eventually make 

 its appearance in this country, have heen on the lookout for it 

 for many years ; but with the exception of the Bartholomew col- 

 lection previously mentioned it has not been found anywhere in 

 the Americas. No Cronartiiim on any species of Ribes and no 

 Peridermium on Pinus strobvs are known to America. The fact 

 that America is the home of the white pine makes the absence of 

 Cronartiiim ribicola especially noteworthy. Magnus, Klebahn, 

 and others have commented upon this and discussed the probable 

 origin of the fungus. The most plausible theory advanced regard- 



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