APPLE-TREE HYDNUM 177 



it is almost certain to become covered with Stereuvi, tlie 

 spores of which might alight on the wounded surface of a 

 living tree. 



Hartig, Die Zersetz. des Holzes, p. 129, tab. xviii. 

 Prillieux, Malad. des Plantes Agric, vol. i. p. 314. 

 Marshall Ward, Trans. Roy. Soc, vol. clxxxix. p. 123, 

 pi. 17-21 (1898). 



HYDNACEAE 



Apple-Tree Hydnum 

 {Hydnum sdiiedermayeri, Heufler.) 



According to Thiimen this fungus is very frequently 

 destructive to apple-trees, developing under the bark, which 

 is killed, often extending for several feet as a fleshy, 

 irregular mass, and bursting through cracks here and there 

 to form its sporocarps on the surface of the bark. 



The fungus is often very large, fleshy, irregularly nodulose, 

 the nodules or pilei producing long spines on their under 

 surface; flesh yellow, externally yellow or pileus tinged 

 flesh-colour. Smell spicy. 



Preventive Means. — Badly diseased trees should be 

 felled and used for firewood. The sporocarps of the fungus 

 should not be allowed to develop. 



Thiimen, Zeitsch. f. Fflanzenkr., vol. i. p. 132. 



,Hydnum diversidens, Fries. — Very shortly stalked, pileus 

 variable in form, whitish, upper surface densely covered 

 with erect, variable, incised teeth ; spines more or less 



M 



