SOME FUNGUS DISEASES OF TREES. 



BY L. H. PAMMEL. 



The researches of Hartig, Tubeuf, Metcalf, Von Schrenk, and others 

 have shown that quite a large number of wood destroying fungi be- 

 long to the Agaricaceac. Hypochnaceae, Polyporaceae, Hijdnanceac, and 

 Thclcphoraccac. 



In many cases these fungi attack the plant through a wound result- 

 ing from a windstorm or from injudicious pruning. 



Heart Rot. 



Heart rot is a very common wood destroying fungus and occurs on 

 the Quaking Aspen {Populus tremuloides) . This species is not abundant 

 except in a few localities in Iowa, though the most important de- 

 ciduous tree in the Rockies from New Mexico to Canada. At times it 

 is seriously affected with fungus diseases in the Rocky mountains. In 

 1908 we found thousands of diseased trees in the Wasatch mountains 

 in Utah. Many trees were dying from a heart rot caused by Fomes 

 igniarius, which is common in eastern North America on the same plant 

 according to Haven Metcalf.^ Saccardo- reports it as occuring on Salix; 

 Winter" on the same host and Querciis. Tubeuf* adds alder, apple, and 

 other deciduous trees; Lindau^ mentions the willow and apple; Massee® 

 and Duggar^ give short accounts of the fungus and its injury to de- 

 ciduous trees. 



The fungus was named Boletus igniarius L." Then Fries^ transferred 

 it to the genus Polyporus (P. igniarius). Subsequently the name 

 Fomes^^ was applied to the perennial species of Polyporus, with a thick 



^Yearbook U. S. Dept. Agrl. 1907.491, pZ. 59, f. I. 



=Sylloge Fung. 6:180. 



^^Die Pilze. Abt. 1:424. 



^Diseases of Plants. Engl. Trans. 433. 



"Handbuch der Pflanzenkrankheiten. 386. 



"Diseases of Cultivated Plants. 373. 



"Fungous Disease of Plants. 464. 



'Fl. Suecia. 1250. 



"Syst. Myc. 1:375. 



^"Nov. Symb. 31. 



