404 GEOGRAPHICAL DISTRIBUTION OF FUNGI 



India [Butler and Bisbv (1931)] occur in Europe. Seemingly 

 this group contains members that are restricted in range, and many 

 of them are confined to the tropics or subtropics. 



Of the operculate discomycetes listed in Seayer's monograph 

 (1928) 35 ° are limited to North America and 61 % are common 

 to both North America and Europe. This group, which is almost 

 wholly saprophytic, is thus quite cosmopolitan. 



Distribution of exotics. Endothia parasitica, the chestnut- 

 blight fungus, is the best known and also the most destructive 

 ascomycete introduced into the United States. It was first noted 

 by Merkel in the New York Zoological Park in 1904 and thence 

 spread with alarming rapidity throughout the entire Appalachian 

 region where Castanea dent at a is native. In 1913 Meyer found 

 that this organism is endemic on Castanea mollissima in northern 

 China. 



Ceratostomella ulmi, causing the so-called Dutch elm disease 

 [Clinton and McCormick (1936)], appeared in Holland in 1919, 

 spread throughout continental Europe and the British Isles, and 

 was first found in the United States in 1930. It is presumed to 

 have been introduced into the United States on burl elm logs. 

 Now it is gradually spreading on American elms in northern New 

 Jersey and other localities in the vicinity of New York City. 



Dasyscypha ellisiana, widely prevalent in the eastern United 

 States on the bark of pines, is a much less spectacular exotic. It 

 was first collected by de Schweinitz in 1931 and does not injure 

 pines in any way. Only recently, how ever, it was found capable 

 of attacking Fsendotsnga taxifolia [Hahn and Avers (1934)], a 

 species that does not grow in the natural range of D. ellisiana. 



Species with erratic distribution. Plausible explanations are 

 lacking to account for the peculiar distributional range of many 

 Ascomvcetes. For example, Urnula geaster, first collected near 

 Austin, Texas, in 1893, was known only from that location until 

 1938, when it was found in Japan. So large and so striking a disk 

 fungus could scarcely have escaped observation elsewhere had 

 it been present. A similar opinion is held regarding Sarcoscypha 

 minuscula, occurring on dead cedar foliage, which is known only 

 from Portugal, Bermuda, and the Yosemitc National Park [Seaver 

 (1942)]. Furthermore, Poronia leporina, which is abundant on 

 rabbit dung in Bermuda [Seaver (1942)|, has been collected in 

 North America only three times during a period of over 50 years. 



