DISEASES CAUSED BY WOUND FUNGI. 37 



from the old stump into the heartwood of the living trees. If the 

 stumps had been painted with creosote soon after the trees were 

 cut, this could not have happened. 



A similar instance was noted some years ago in a catalpa planta- 

 tion in eastern Kansas, where the trees had been cut off while they 

 were still young in order to stimulate the production of a single large 

 shoot. The high percentage of diseased trees in this plantation is 

 directly ascribed to the fact that the fungus had entered the new 

 shoots from the old stumps. It would have been easy and com- 

 paratively inexpensive to have coated the cut surfaces of the stumps 

 with coal-tar creosote at the time the trees were cut. Where this 

 can be done, especially where coppice growth is expected, as in the 

 case of the chestnut, such wound treatment may be found practi- 

 cable and will at all times be advisable. 



RED HEART-ROT CAUSED BY POLYPORUS SULPHUREUS. 



The sulphur polyporus {Polyporus sulphureus (Bull.) Fr.) is found 

 on a large number of deciduous forest trees, but chiefly on oaks 

 (Quercus spp.), chestnut (Castanea dentata (Marsh.) Borkh.), maples 

 (Acer spp.), black walnut (Juglans nigra L.), butternut (Juglans 

 cinerea L.), alder (Alnus sp.), locust (Robinia pseudacacia L.), apple 

 (Pyrus mains L.), pear (Pyrus communis L.), etc. It is widely dis- 

 tributed throughout the United States and Canada and in most of 

 the forest regions of Europe, where it is regarded as a destructive 

 parasite, both on deciduous trees and conifers (32). Reference to 

 the disease caused by this fungus was first made in this country by 

 Galloway and Woods (27), and later by von Schrenk (78). 



The fruiting bodies of the sulphur polyporus are among the most 

 conspicuous of the larger fungi found in the forests. They form a 

 series of shelves, from 2 to 20 or more, overlapping one another. 

 Sometimes they form very close together, so as to produce a large, 

 round mass about the size of a person's head. (PL IV, fig. 1.) The 

 upper surfaces at first are a bright orange-red, with a brighter red 

 at the rims. As they grow older they assume a distinct sulphur- 

 yellow color, which is also the color of the under surface. When 

 young, the upper surface is very moist, somewhat hard, and when 

 bruised turns brown. The whole fungus is soft and fleshy when 

 young, and when squeezed a clear yellowish liquid exudes. As the 

 plant grows older it becomes much harder, and shortly after maturity 

 becomes quite firm and brittle. The fruiting bodies of this fungus 

 very rarely remain on the tree for any length of time, because they 

 are attacked soon after reaching maturity by a number of insects, 

 which speedily destroy them. The fungus is also eagerly sought by 

 mushroom hunters on account of its excellent and well-known odible 

 qualities. 



149 



