296 MANUAL OF TREE DISEASES 



The control of this root-rot would require such measiu-es as are 

 described under the shoe-string root-rot (see page 78). 



Befebencbs 



Sehrenk, Hermann von. Polyporus Schweinitzii. In Some diseases 



of New England conifers. U. S. Dept. Agr. Div. Veg. Phya. 



and Path. Bui. 25 : 18-24, pis. 1-2. 1900. 

 Hedgcock, G. G. Notes on some diseases of trees in our national 



forests. IV. Phytopathology 4 : 181-188. 1914. 

 Hartig, R. Polyporus mollis Pr. In Die Zei;setjzungserscheinungen 



des Holzes, etc., pp. 49-53, pi. 9. 1878. 



Yellow Root-Rot 



Caused by Sparassis radicata Weir 



Pines are seriously damaged in the Northwest by the yellow 

 root-rot. In the same region fir, spruce and larch are also 

 affected. Yellow sheets of mycelium are formed in the bark 

 of the affected roots. Later the sapwood and in some cases 

 the heartwood of the roots is decayed. Large, white, fleshy 

 fruiting-bodies are produced on the groimd, which are con- 

 nected with the diseased roots by long tuber-like growths. 

 Further details concerning this root-rot will be found imder 

 fir diseases, on page 170. 



Brown Root- and Butt-Rot 



Caused by Fames annosus Fries 



Pines are occasionally affected by this root- and butt-rot. 

 The wood of the roots and butt of the pine is decayed, but the 

 fungus' does not extend its activities into the trunk because of 

 the high resin-content of the wood. The wood becomes in 

 turn bluish, yellowish and red-brown. White pockets with 

 black centers are visible for a time in the brown wood, but later 

 these coalesce and leave the brownish summer-wood of the 



