6 BULLETIN 722, U. S. DEPARTMENT OF AGRICULTURE. 
The fungus is most abundant and of greatest consequence in western 
Montana, Idaho, Oregon, Washington, and British Columbia. 
THE DISEASE CAUSED BY ECHINODONTIUM TINCTORIUM. 
OUTWARD SIGNS OF THE DISEASE. 
To be able to recognize or discriminate between the more dangerous 
and less harmful diseases should be a part of the everyday knowledge 
of the forest officer in charge of the marking. The following state- 
ments will be of some value in this respect. 
The decay-producing fungus proper is the mycelium in the wood, 
not the ‘‘conk” (fig. 5) without. The appearance of a fruiting body 
Fic. 3.—Sporophore of Echinodontium tinctorium, showing upper surface. 
is in most cases an index of the intensive development of the fungus, 
at least within a certain volume of the tree infected. It means that 
a good part of the food materials of the heartwood at that point 
are exhausted. A single average-sized sporophore situated on the 
first 16 feet of the trunk for all practical purposes may be taken to in- 
dicate an unmerchantable condition of the heartwood of all pomts 
below and into the next 16-foot log above the first. A sporophore 
situated well up on the trunk may be taken to indicate undesirable 
material throughout the main part of the tree. Little need be said 
concerning the presence of more than one sporophore. It will be 
observed that the largest usually has smaller ones above and below it. 
