AUTOBASIDIOMYCETES 467 



The sporophore varies in form from the shape of a hoof to that 

 of a thick bracket. The upper surface is, with age, black, indurated, 

 and cracked, also showing concentric ridges ; while the lower sur- 

 face is commonly, during the growing season, cinnamon-brown. 

 The mycelium grows within the heartwood, which is generally 

 converted to a soft mass, bordered by black rings. 



Fomes fomentarius (L.) Fr. This fungus occurs in situations 

 similar to those mentioned for the preceding organism. It is far 

 more common upon beech, yellow birch, and hard maple. The 

 sporophores may be found upon living trees, but they are produced 

 in far greater abundance after the death of the tree affected. They are 

 distinctly hoof-shaped (Fig. 230), with a grayish upper surface and a 

 lower surface which is light brown or gray-brown during the summer. 



Fomes Pinicola Fr. In the moist temperate regions this fungus 

 induces a decay in a variety of conifers, especially pines (Pinns spp.), 

 spruces (Picea spp.), and balsam (Abies balsamed). The sporo- 

 phore is a broad, relatively thick bracket, with a creamy white 

 under surface. The upper surface is dark, generally with broad 

 ridges, the lower of which may be reddish to bright red-brown 

 in color (Fig. 231). The sporophores generally develop after the 

 death of the tree. 



Fomes applanatus (Pers.) Wallr. The sporophores of this fun- 

 gus constitute the most conspicuous forest brackets. The fungus 

 occurs upon a variety of deciduous trees, but it is regarded as more 

 commonly saprophytic. In any event, it is important in the decay 

 of trees injured by fire or water, and of fallen trunks. 



X. A BROWN ROT OF CONIFERS 



Trametes Pint (Brot.) Fr. 



Hartig, R. Trametes Pini Fr. Wichtige Krankheiten der Waldbaume. 

 pp. 43-61. pi. 3. figs. 1-19. 1874. 



Among the various species assigned to the genus Trametes 

 there are some important wood-destroying fungi. Trametes Pini 

 is common in the United States throughout the coniferous forests. 

 In the Ozark pine forests of Missouri it is the chief cause of loss 

 from fungi. In some regions which have been cut over there 

 have been left thick forest groves, and these often consist very 



