122 MANUAL OF TREE DISEASES 



are killed before they mature and appear as frost-injured. 

 The mycelium is perennial in the twigs. The leaves of the 

 normal branches also become spotted and curled. Small 

 yellowish blisters are formed which later turn to a dull red. 

 The fimgus causing this disease is a close relative of the leaf- 

 blister fungus on oak (see page 239) . The disease on the buckeye 

 does not cause very much damage to the trees, since the leaves 

 naturally remain on the tree only from April to early summer. 



Reference 



Harkness, H. W. The curled leaf {Ascomyces deformans). Zoe 1 : 

 87-88. 1890. 



White Sapwood-Rot 



Caused by Collybia veluHpes Curtis 



The sapwood of horse-chestnut is sometimes destroyed by 

 this toadstool. The wood becomes whitish and soft. The 

 spores of the fungus find entrance through wounds in the bark. 

 The fruiting-bodies of the causal fungus are toadstools with 

 yellow or brownish tops and gills. The bases of the stalks are 

 covered with a brown or black velvety growth of hairs. A 

 fuller discussion of this disease will be found under basswood 

 diseases, on page 103. 



