Chapter 17 

 GEOGRAPHICAL DISTRIBUTION OF FUNGI 



Plant geography is admittedly a tremendously valuable branch 

 of botanical knowledge, and its fundamentals, in relation to mosses, 

 ferns, and especially seed plants, are now relatively well under- 

 stood. Apparently, however, for reasons that will become mani- 

 fest in the discussion which follows, any consideration of the geo- 

 graphical distribution of fungi at this stage of mycological devel- 

 opment has a limited usefulness, partly because to date this phase 

 of inquiry has received little attention. Nevertheless it should 

 eventually come to be recognized as having a very practical and 

 very general interest. 



Bisby (1933) has said, "Mycologists have been able to map with 

 accuracy the geographic distribution of comparatively few fungi." 

 The worker who turns his attention to this subject is early im- 

 pressed with the fact that vast portions of the earth's surface re- 

 main completely unexplored for fungi and hence are literally terrae 

 incognitae fungornm. Such distributional data as are contained 

 in monographs on special groups of fungi or in accounts of species 

 of economic importance afford a basis for certain generalizations. 

 Much additional pertinent information has been catalogued in 

 herbaria but remains unpublished and hence quite unavailable. 



In a report Bisby and Ainsworth (1943) state that the exact dis- 

 tribution of but few of the 3600 genera including 37,000 "good" 

 species of known fungi has been determined. Distribution of 

 genera by continents, as given by Bisby (1943), is as follows: 

 Europe 1800, North America 1700, South America 1100, Asia 

 1100, Africa 800, and Australia-New Zealand 600. 



On first thought it might appear that the nutritional factor 

 should be all important in determining the distributional range of 

 fungi for the reason that they are either saprotrophic or para- 

 trophic in food habits. Food is not, however, the sole factor, for, 

 just as with holophytic plants, natural distribution has been found 



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