'WITCHES' BROOMS' OF CHERRY 89 



' WITCHES' BROOMS ' OF CHERRY 



(yExoasciis cerasi, Sadeb.) 



This disease, which is not uncommon on the Continent, 

 is rare in Britain. Cherry-trees attacked by this disease 

 show dense tufts of branches growing as it were from a 

 single point, and presenting the appearance of the abnor- 

 mal developments so much more abundant on the birch, 

 and known popularly as 'witches' brooms,' 'witches' besoms,' 

 ' birds' nests/ etc., in different parts of the country. These 

 tufts never bear fruit, and the leaves produced on such 

 abnormal branches are thick and leathery, of a sickly 

 greenish yellow or tinged red, and in due course present 

 a hoary appearance due to the presence of the fruit of 

 the fungus on their surface. 



Preventive Means. — The best way of getting rid of 

 the fungus, the mycelium of which is perennial in the 

 diseased parts, is to cut out the tufts, which not only 

 disfigure the tree, but continually add to the chances of 

 extending the disease. 



The following species also occur in Britain : — 



'WITCHES' BROOMS' OF SILVER BIRCH 



{Exoascus hirgidus^ Sadeb.) 



This forms the familiar dense tufts of branches on the 

 silver birch. 



'WITCHES' BROOMS' OF ALDER 



{Exoascus a?nentorti?n, Sadeb.) 



This species deforms and much enlarges the scales of 

 the female catkins of the alder. 



