24 



BULLETIN 124.1, U. S. DEPARTMENT OF AGRICULTURE 



little if any poison. Cases of poisoning occur in the winter on areas 

 where feed is scanty. 



All the known cases of poisoning have been of sheep and goats. 

 Animals eating the seed show depression, generally accompanied with 

 diarrhea. In fatal cases the symptoms are not especially pro- 

 nounced; but the animals become weak, have labored breathing, and 

 die with very little struggling. Considerable time elapses between 

 the feeding and the appearance of symptoms, sometimes as much as 

 24 hours. The symptoms, too. may continue several days, so that 

 poisoned animals require special care until after complete recovery. 

 Figure 15 shows a sheep poisoned by the poison bean. 



Figure 14. — A sheep poisoned by lupine in the typical attitude of butting against some 



object 



LOCO WEEDS (SPECIES OF OXYTROPIS AND ASTRAGALUS) 



"Without any doubt the most destructive of all the poisonous plants 

 are those going under the general name of loco. That extensive 

 losses of domestic animals have been caused by loco plants has been 

 believed for a long time, but it is only within the last few years that 

 exact evidence, by careful experiments, has shown definitely that 

 these plants produce the effect which has been popularly ascribed to 

 them. A great deal of interest attaches to these plants because of 

 their wide distribution and the large number of animals that have 

 been poisoned by them, including cattle, horses, goats, and sheep, and 

 also because of the difficulty of actually proving the existence of a 

 poisonous principle in the plants themselves. 



The loco weeds have had a place in romantic literature, as it has 

 frequently been asserted that they produce the same effect on human 



