DRUG PLANTS 371 



When North America was settled by white men, a flora with 

 many new plants unlike those used in European "remedies," 

 confronted them. The physiological eff'ects of countless species 

 of plants have been tabulated from experimental or accidental 

 use, until today there is scarcely a known genus of plants which 

 has not been tried out in medicine. Even today, the science of 

 medicine is not an exact one; the same drug does not aff'ect all 

 human organisms in precisely the same way, but a more exact 

 knowledge of the nature and properties of plant drugs is at hand 

 now, and is being better used than ever before. In fact, present 

 day medicine is no longer content with plant drugs in their 

 original form, but seeks through the aid of chemistry, to refine 

 these substances in such a way as to discard portions which have 

 an undesirable physiological eff^ect, while retaining or even 

 strengthening the beneficial portions of the compound. 



The most valuable of the plant drugs have been standardized 

 by the United States Government to prevent harmful adultera- 

 tion of them. Only a few species of drug plants are cultivated, 

 most of them growing wild in sufficient quantity at the present 

 time. They are scattered all over the world, especially in the 

 tropics. Their medicinal value is due to presence in the tissues 

 of chemical substances that bring about definite physiological 

 reactions in the human body. Under normal body conditions 

 such substances are unnecessary, but when disease causes the 

 upsetting of some particular function, then medicines help to 

 restore such a condition of normality. The most important plant 

 drugs are chemical substances kno.wn as alkaloids, which are 

 made up of carbon, hydrogen, oxygen, and nitrogen. There are 

 many ways in which to group plant drugs for discussion. Such 

 grouping might be made on the basis of their chemical nature 

 or the medicinal effect of the substances; or with regard to the 

 natural relationships of the plant sources. Still another is based 

 upon the part of the plant which is used as the drug source. 



Drugs Obtained from Flowers and Fruits 



Opium is the dried juice or latex of the opium poppy, native 

 in western Asia but now occurring in most countries as a weed. 



