420 ERGOT. 



serve as hosts for the cluster-cup stages of rusts, are the best 

 methods of keeping them within check. 



ASCOMYCETES. 



5. Ergot. {Claviceps, Sp. Sclerotium clavus of authors.) 

 Black, purple or dark gray spurs in the flowers of cereals and of 

 various wild and cultivated grasses. 



The officinal ergot, to be found in most rye-fields toward the 

 end of summer, appears in the form of curved purple or black 

 spurs, often an inch long and 3-16 in. in diameter, which replace 

 the grain in one or more flowers of a spike, thus giving rise to the 

 popular name of spurred rye, often applied to it. Spurs of the 

 same nature, but usually shorter and stouter, are also common 

 in the heads of wheat. Similar bodies, varying much in size, 

 shape and color, are found in the flowers of many grasses. On 

 the rush-salt grass they are very long and slender, and rather 

 pale. On wild rice they are short, and even stouter than the 

 spurs of wheat ; while on smaller grasses, like red-top, Timothy, 

 blue-grass, etc., they are much smaller, and closely resemble the 

 pellets of mice. 



These spurs are the resting form, or sclerotia, of a fungus 

 which appears at the base of the young grain, when the grasses 

 are in bloom. As it grows it gradually takes the place of the 

 grain, the remains of which are pushed up at its end. While 

 young, the fungus gives off a sweetish, ill-smelling fluid, that 

 contains myriads of microscopic spores which are carried from 

 plant to plant by flies, beetles and other insects that feed on the 

 fluid, and so play an important part in spreading the disease. 

 When the spurs have reached their growth they harden, and fall 

 to the ground, where, as a general thing, they remain unchanged 

 till the next spring, when each bears a number of small, stalked. 



Fig. 165.— 1, 2, 3, 4, Grasses affected with Ergot appearing as black spurs. (From 

 the U. S. Dept of Agrl.) 



