402 GEOGRAPHICAL DISTRIBUTION OF FUNGI 



was a very wet season, however, this fungus was noted on tobacco 

 flowers in the vicinity of Durham, North Carolina. 



DISTRIBUTION OF ASCOMYCETES 



This discussion of the distribution of Ascomycetes must of 

 necessity be fragmentary and is in no sense proportional to the 

 vast bodv of data on this group that has been accumulated. 

 Nevertheless the material is believed to be representative for the 

 group as a whole. Many species of great economic importance 

 have been spread by man to the extent that they now occur in all 

 countries where the hosts are cultivated. The severity of the dis- 

 eases which thev cause is modified, to be sure, by latitude, by 

 seasonal differences in climate, or by application of palliative or 

 control measures. Fungi of this kind include Taphrina deformans 

 and Sclerotinia jracticola on peach and Venturia inaeqitalis on 

 apple. Venturia inaequalis occurs througout the United States, 

 Mexico, and Canada, but it rarely is found in the Coastal Plains 

 of the southeastern United States. In Europe it has been noted in 

 the British Isles, Belgium, Netherlands, Portugal, France, Switzer- 

 land, Norway, Sweden, Denmark, Germany, Austria, Czecho- 

 slovakia, Russia, Greece, and Bulgaria. Moreover it is reported 

 from India, New Zealand, Tasmania, Rhodesia, Morocco, Argen- 

 tina, and Peru and mav therefore be presumed to be global in 

 distribution. 



The observations of Fawcett and Lee (1926) show that Dia- 

 porthe citri on citrus is another in the same group of organisms. 

 This fundus was first studied in Florida in 1892 and was subse- 

 quently found in Brazil, Argentina, Mexico, the West Indies, 

 China, Japan, Palestine, Algeria, South Africa, and South Aus- 

 tralia. Its symptom-complex includes dying bark of twigs, stem- 

 end rot of ripe fruits, and melanose markings on leaves, twigs, and 

 fruits. The melanose form of the disease does not occur in Cali- 

 fornia or at least is very rare, whereas it is always very abundant 

 in central Florida. 



The fact that pathogenic species, especially, are capable of 

 maintaining themselves for indefinite periods saprogenically, as is 

 Thielavia basicola (Tknelaviopsis basicola), constitutes a compli- 

 cating factor in distribution. Thielavia basicola attacks many spe- 

 cies of legumes, especially beans, clovers, lupins, peas, soybeans, 



