ERGOT 



281 



aguilinum), a species widely distributed in North America, 

 should be mentioned as one of the poisonous plants to be reckoned 

 with. Few cases of stock poisoning from fern are on record in 

 the country, but it is likely that all classes of stock would be 



susceptible to the poison 

 if they were to feed gen- 

 erously upon the plant. 

 Some losses in sheep are 

 reported in the North- 

 west from the eating of 

 bracken fern (Fig. 105). 



Ergot {Claviceps pur- 

 purea). — Ergot is a par- 

 asitic fungus, having the 

 appearance of a black 

 spur, straight or slightly 

 curved, one-fourth to 

 one-half of an inch in 

 length, which grows in 

 theheads of some grasses. 

 It occurs on a number 

 of host plants, such as 

 wild rye (Elymus), vari- 

 ous meadow grasses, 

 bluejoint, couch grass 

 (Agropyron), Junegrass 

 (Koeleria), and others. 

 It occurs most frequently on wild rye, and may be present 

 wherever that plant grows (Fig. 106). It usually appears in 

 the middle of August and remains until late in the fall. 



Ergot produces two forms of poisoning — the nervous form 

 and the gangrenous form. Symptoms in both forms of the 

 disease are fatigue, cold sweat, nervousness, paralysis of the 

 entire body beginning with the tongue and throat, and digestive 

 disturbances. In pregnant animals the poison often causes 

 abortion. The gangrenous form of ergotism is characterized 

 by swelling and the formation of dry gangrene of the hoofs, fol- 



FiG. 104. — WILD CHERRY (Prunus demissa). 



