DISEASES OF THE MULBERRY ] 165 



period. It seems that the form of Armillaria which 

 attacks the three kinds of trees above mentioned is 

 particularly virulent, because Rosaceous trees, such as 

 the loquat, the peach, the pear, the apple, the plum etc. 

 succumb rapidly to the disease if planted on the spot 

 where a mulberry or a fig tree had been killed by it, 

 but on the other hand, neither the mulberry nor the 

 fig tree are usually affected by the disease if planted 

 on the spot where a rosaceous tree was killed by it. 

 As Armillaria attacks many species of trees and shrubs, 

 both fruit-bearing and ornamental, and will be frequently 

 referred to in these pages, a brief description of this 

 fungus will be useful. 



Armillaria mellea Vahl. is a gregarious fungus, 

 occurring in clumps of 3 to 5 or in large clusters of 

 30 to 60 individual mushrooms generally at the foot 

 of a dead tree, or on the underground stump or large 

 roots of a dead tree or shrub. The stipes or stem 

 is 10 to 15 c. m. in height, and i to 2 c. m. in thickness, 

 cylindrical, more or less contorted or flexuous, solid, 

 brown below near the base, and lighter or white above, 

 where it is striated and scaly or floccose. There is 

 a well-marked ring high on the stipes and close to 

 the pileum. The pileum is plane, 6 to 12 c. m. in 

 diameter, clear brown or honey-coloured, darker towards 

 the centre, concave at maturity. The margin is irregular 

 and wavy, sometimes bent downwards. The pileum 

 is firmly attached to the stipes, and is dry, almost 

 velvety. The laminae are decurrent on the stipes ; they 

 are white, and the spores are white. This mushroom 

 is poisonous. It is important to collect these clusters 

 of mushrooms as soon as they appear above ground, 

 and burn them to prevent the formation of spores, at 

 the same time it is obvious that no stumps of dead 

 trees ought to be allowed to remain in the ground. 



Wounds in the stem of adult mulberry trees heal 

 very slowly. They are liable to set up an exudation 



