WEEDS AND POISONOUS PLANTS 339 



Spite of the fact that they are poisonous in the condition in 

 which they are gathered. Thus, the fresh shoots of the 

 pokeweed are used Hlfe asparagus ; but the water in which 

 the shoots are first boiled must be discarded because of the 

 poisonous substance dissolved iii it ; and it is important that 

 no part of the root be eaten. The fruits of the horse-chestnut 

 and its relatives, the buckeyes, are poisonous ; but those of 

 the California buckeye are said to be used by Indians after 

 the poisonous substance is removed by proper treatment. 

 The fruits of the horse-chestnut are fed to cattle in England, 

 the poison being first removed. The root of cassava, from 

 which tapioca is obtained, is another illustration. The 

 tapioca is the starch of the root ; to obtain it the root is 

 ground up and thoroughly washed to remove the poisonous 

 substance that it contains. Other plants that have been 

 found to be more or less poisonous are the lily-of-the-valley, 

 staggerbush, branch ivy, and false jessamine. 



355. Plants Especially Dangerous to Animals. — Impor- 

 tant members of this class are numerous species of larkspur. 

 Some European larkspurs have long been considered poison- 

 ous to stock ; and serious losses of cattle and horses occur in 

 the mountainous grazing regions of the western United States, 

 caused by the eating of the native larkspurs. Curiously 

 enough, experiments seem to show that sheep are not poisoned 

 by these plants, although there are differences of opinion upon 

 this point. Serious damage is caused to horses, cattle, and 

 sheep in the western United States by certain plants, poison- 

 ing by which at first causes a sort of hallucination or insanity, 

 for which reason the plants causing the trouble are called 

 " loco weeds." The disease ends after some months in the 

 death of the poisoned animal. The woolly loco weed, found 

 from South Dakota and Wyoming to Texas and New Mexico, 

 is an Astragalus ; the stemless loco weed, which ranges from 

 British America to Mexico, is an Oxytropis ; both are mem- 

 bers of the pulse family. Some species of lupine, belonging 



