Trees and Timber 361 



Infective material should be burned, wounds avoided, 

 and excision practiced in case of valuable trees. 



Red heart-rot, Brown-checked wood-rot ^^^' ^^^ (Polyporus 

 sulphureus Fr.). — The conifers, also oak, chestnut, maple, 

 walnut, butternut, alder, locust, apple, pear, cherry, and 

 many other trees are affected. It is widely distributed, de- 

 structive, and is especially common on shade and ornamental 

 trees. 



The many-pored edible annual sporophores consist of a 

 series of overlapping shelves, two to twenty or possibly more, 

 with the upper surface in early stages a bright orange-red; 

 later they are sulphur-yellow both above and below. The 

 upper surface when bruised is brown. The sporophore is 

 soft and fleshy when young, growing hard and brittle with 

 age. This fungus abounds on knots and stumps. The rotted 

 wood resembles red-brown charcoal and following decay 

 bears concentric and radial cracks due to shrinkage. In these 

 cracks are large sheets of fungous wefts. 



Diseased trees should be cut and l:)in'ned to prevent 

 infection. 



Piped-rot (Polyporus sps.). — The oak, chestnut, beech, 

 and birch are susceptible to this rot, which is limited to the 

 heartwood and is characterized by irregular, small, pocket- 

 like patches of white fiber. These regions first appear in the 

 wood as small, lenticular areas which increase, coalesce, and 

 change into small pockets. These frequently become filled 

 with a dark, red-brown mycelium. The speckled character 

 of the wood is a distinctive mark. 



White-rot (Hydnum erinaceus Bull.). — Although ob- 

 served upon many kinds of trees, oaks are chiefly affected. 

 The rotted wood is soft and wet, with numerous holes full of 

 light yellow fioccose mycelium. The fleshy sporophores are 

 white, 1 to 25-30 cm. in diameter, nearly spherical, and 

 consist chiefly of immense numbers of white spines upon 

 whose surfaces the spores are borne. 



Heart-rot •''^^ (Fomes fulvus Gill.). — In Missouri and 

 Arkansas this heart-rot is found upon birch and a number of 



