THE SCLEKOTIUM DISEASE OF CLOVER, 427 



white mycelium tliat bears such numbers of white spores as to- 

 suggest a dusting of meal or flour. 



This mildew is usually found through the- 

 entire open season on grass growing in damp 

 and shaded positions; it is especially abundant 

 on June grass. Its cobwebby mycelium; which 

 does not penetrate the leaves, does not at first 

 appear to injure them but in time they succumb 

 Fig. 172. and dry up. Through the summer it spreads 



by means of its light conidia, that are easily blown about and 

 germinate quickly while fresh, though they are unable to live 

 through the winter. On the dead leaves small, black fruit- 

 bodies, scarcely visible to the naked eye, are formed, in which 

 winter-spores are produced in short-stem asci. (Fig. 172 is the 

 illustration for the grass-mildcAV. ) 



Usually grasses do not suffer niudi from mildew, except in 

 damp and shaded places. Drainage is likely to prove beneficial 

 where it is troublesome. 



1 1. The sclerotiiim disease of clover, {Peziza cihonoides, ¥.} 

 On clover, causing a browning of leaves or stem, which are soon 

 covered in spots by a white mold that ultimately forms solid,, 

 wavy, black bodies, often ^ in. long, white within. 



In Europe, clovers are occasionally attacked by this fungus, 

 which is very destructive when it occurs. The entire plant 

 becomes filled with a mycelium which soon kills it and afterward 

 breaks through in places, forming black sclerotia on the various 

 parts of the decaying plants as winter approaches. These bodies 

 lie dormant in the soil until the following summer, when they 

 produce fruit-bodies in the form of wavy stems, bearing brown 

 disks or inverted cones, -^^ to .j in. in diameter, on their ends. 

 When these reach the surface they shed their spores and so spread 

 the disease. 



Draining the soil well, and especially replacing clover by 



