250 MANUAL OF TREE DISEASES 



References on Beown Checked Wood-Rot 



Schrenk, Hermami von, and Spaulding, P. Red heart-rot caused by 



Polyporus sulphureus. In Diseases of deciduous forest trees. 



U. S. Dept. Agr. Bur. PL Ind. Bui. 149 : 37-39. 1909. 

 Schrenk, Hermann von. Polyporus sulphureus (Bull.) Fr. In Some 



diseases of New England conifers. U. S. Dept. Agr. Div. V^. 



Phys. and Path. Bui. 25 : 40-44. 1900. 

 Atkinson, G. F. Polyporus sulphureus. In Studies of some shade 



tree and timber destroying fungi. Cornell Univ. Agr. Exp. Sta. 



Bui. 193:208-214, figs. 64-70. 1901. 

 Hartig, R. Polyporus sulphureus Pr. In Die Zersetzungserschei- 



nungen des Holzes etc., pp. 109-113, pi. 14. 1878. 



Common White Wood-Rot 



Caused by Pomes igniariiis Fries 



Oaks, especially those species belonging to the black oak 

 group, often are found with the heartwood reduced to a white 

 punk. Beech and poplars, especially the aspen and balm of 

 Gilead, are the most destructively and commonly affected of 

 the various kinds of deciduous trees attacked by this fungus. 

 In Europe this is the most important of the wood-rots of the 

 oak in the forest. In the United States, the brown checked 

 wood-rot of oak seems to be more destructive. This is es- 

 pecially true outside the forest, where shade and ornamental 

 oaks are concerned. The sapwood of oak is more commonly 

 invaded than is the sapwood of the other trees affected, re- 

 sulting in stag-head and dead limbs. The sporophores and 

 nature of the rot which are similar for all kinds of trees are 

 described under poplar diseases, on page 305. 



White Pocket Heaktwood-Rot 



Caused by Polyporus Rheades Fries ( = Polyporus dryophilus Berkeley) 



The heartwood of many species of oaks and sometimes of 

 poplars is destroyed by this disease. Although found in oaks 

 practically over the entire United States, this rot is particu- 



