406 GEOGRAPHICAL DISTRIBUTION OF FUNGI 



endemic to the Mediterranean area. It was first noted in the 

 United States in 1919 and was early studied by Tisdale, Dugan, and 

 Leighty (1923) and Griffiths (1924). It has been recorded from 

 China, Japan, India, Australia, Tasmania, South Africa, Egypt, 

 Tunis, Italy, Cyprus, and Spain. Dissemination in Australia is 

 attributed to horses that are permitted to forage on wheat straw; 

 the smut spores pass intact through the alimentary tract and then 

 grow in the droppings. 



Distribution of rusts. More is known about the distribution 

 of rusts than that of any other basidiomycetous group. Arthur 

 (1929) considers Europe and North America as the best-explored 

 regions of the earth for rusts, and he states that, as far as their 

 rust flora is concerned, yast areas of other continents remain 

 almost wholly unknown. The Genus Melampsora, according to 

 Cunningham (1931), constitutes the only member of the Melamp- 

 soraceae that is world-wide, most other rusts of this family being 

 confined to Europe, Asia, and America. Alilesia also is regarded as 

 world-wide by Faull (1932). Another distributional peculiarity 

 noted by Cunningham (1931) is that species of Milesia and Puc- 

 ciniastrum, but none of Cronartium, are found in New Zealand, 

 whereas species of Cronartium, but none of Milesia nor of Puc- 

 ciniastrum, thrive in Australia. In connection with Uredinopsis, 

 attacking ferns and firs, Faull (1938) states that 13 species occur 

 in the Western Hemisphere north of Mexico, 3 in Europe, 12 in 

 Asia, and 1 in Africa. Uredinopsis m&crosperma is the most widely 

 dispersed one, but strangely it is entirely absent in many regions 

 where its fern host, Pteridium latiusculum, thrives. Some species 

 have very limited ranges, such as U. adianti in northeastern Asia 

 and U. investita in the mountains of Guatemala, both on Adian- 

 tum. However, although U. mayoriana is known from Colombia, 

 far from the range of fir, it is capable of producing aecia when 

 artificially inoculated on fir. 



Of the 33 species and 2 varieties of Milesia, also fir-fern rusts, 

 recognized by Faull (1932), only one, Milesia vogesiaca, is com- 

 mon to both the Old World and the New World. Nine species 

 have been taken in the United States and Canada, 7 in Central 

 America, northern South America, and the West Indies, 13 in 

 Asia, 1 1 in Europe, 2 in Africa, and 1 in Australia. Many species 

 of .Milesia have the ability to perpetuate themselves for years in 

 the entire absence of species of Abies, which are the aerial hosts. 



