26 



Following this start, pharmacognacists gradually brought 

 together the knowledge of medicinal plants from all parts of 

 the earth and sought to determine more accurately the chemical 

 and biological properties of these plants. Today this body of 

 data is collected encyclopedically in the Pharmacopoeias and 

 Dispensatories.- 



Our most valuable medicinal plants are collected from far 

 and near. The following is a selection of some of the more im- 

 portant drugs of vegetable origin, their sources, and uses. 



I — Most Important Vegetable Drugs 



1. Digitalis. The leaves of the flowering plant D. purpurea L. 



(Foxglove) are dried and used in preparation of a fluidex- 

 tract, infusion or tincture. The active principles, gluco- 

 sides, also are employed. It is probably our most useful 

 heart stimulant. The infusion is used as a diuretic. Culti- 

 vated extensively. 



2. Strophanthus. The ripe seeds of S. Komhe Oliv., of tropical 



East Africa, are made into a tincture. Its action is similar 

 to that of Digitalis. Active principle: one or more gluco- 

 sides. The natives of Africa use it as an arrow-poison, 

 much as curare (Strychnos) is used among the South 

 American Indians. 



3. Opium. Derived from the latex of the incised, unripe fruit 



(capsule) of the opium poppy, Papaver somniferum L. It 

 contains many alkaloids of which morphine is the most 

 important. Its narcotic properties are well known. Culti- 

 ^'ated in the Orient, chief source of the world's supph'. 



4. Coca. The dried leaves of Erythroxylon Coca Lam., culti- 



vated from time immemorial at high elevations in the 

 Andes. Cocaine is extracted from the lea\-es and used 

 chiefly as a local anaesthetic. 



5. Ergot. The resting mycelium (sclerotiumj of the fungus 



Claviceps purpurea (Fries) Tulasne which replaces the 

 grain of grasses, especially rye. Ergot is prepared for use 

 as a fluidextract, infusion, or tincture. Its alkaloids also 

 are employed. The most valuable application is in the 



- Official in this country are The Pharmacopoeia of the United States of 

 America, XI rev. Easton, Pa., 1936, and The Dispensatory of the United 

 States of America XXI ed., Philadelphia and London, 1926. 



