236 



POISONING. 



PRUNACE.E (plum FAMILY). 



* Prunus caroliniana. — The laurel cherry, or mock orange, is native 

 in the south-eastern quarter of the United States, and is there often 

 cultivated for hedges. The half-withered leaves and the seeds yield 

 prussic acid, and .are poisonous when eaten hy animals. 



* Prunus serotina. — The wild black cherry is a valuable forest tree 

 which ranges througliout the eastern half of the United States. Cattle 



are killed by eating the partially 

 withered leaves from branches 

 thrown carelessly within their 

 reach or ignorantly offered as 

 food. The leaves of various other 

 wild and cultivated cherries are 

 probaljly poisonous to cattle in 

 the same way. 



VICIACE.E (pea family). 



Aragallus lambertii. — The 



Lambert, or stemless loco weed, 

 is, next to the following species, 

 the best-known representative of 

 a large group of closely related 

 plants which are native to the 

 western half of the United States, 

 and are known as loco weeds on 

 account of the peculiar excited 

 condition wdiicli they induce 

 in animals that eat of their 

 leaves. Horses and cattle are both 

 affected, but the chief damage is 

 done to horses. After being per- 

 mitted to graze on any of these 

 plants the animal acquires an un- 

 natural appetite for them, and soon refuses all other kinds of food. It 

 rapidly becomes unmanageable, shows brain symptoms, and finally dies 

 from lack of proper nourishment. 



Astragalus mollissimus. — This, the woolly loco weed, is perhaps the 

 best known of all the loco weeds. It is the species most abundant in 

 Colorado, where from 1881 to 1885 nearly $200,000 was paid out in 

 l)ounties in an attempt, to exterminate it. The plant is still abundant 

 in that State, and reports of the damage done by it continue frequent. 



Fig. 87. — Black cherry {I'rKniis serotina), 

 one-third natural size. 



