Economic Importance of Plants 269 



deadly of our poisonous plants. Poisonous mushrooms, such as the death 

 cap (Amanita phalloides) and the fly amanita (Amanita m,uscaria) , are 

 extremely dangerous. Unless one knows mushrooms very well, there is 

 a great possibility of eating the poisonous varieties. 



A few poisonous drugs of plant origin may be listed as follows: 

 Opium is obtained from the dried, milky juice of the seed pods of the 

 opium poppy (Papaver somniferum) of the poppy family. Opium con- 

 tains numerous alkaloids and is used to induce sleep, to relieve pain, and 

 for certain relaxations. Morphine (C17H19NO3) is one of the most im- 

 portant alkaloids present in the opium poppy. Tobacco is the dried and 

 cured leaves of the tobacco plant. The tobacco plant of Virginia is 

 Nicotiana tabacum of the nightshade family. The tobacco leaves possess 

 an aroma which is due to a volatile substance. The chief active con- 

 stituent of tobacco is an alkaloid known as nicotine (C10H14N2) which 

 is a very potent poison. Quinine (C12H24N2O2) is an alkaloid obtained 

 from the bark of the calisaya tree (Cinchona calisaya) of the madder 

 family. Quinine is a deadly poison to the protozoan parasites which 

 cause malarial fever (Fig. 176). Strychnine (C21H22N2O2) is an alkaloid 

 obtained from the seeds of the nux vomica tree (Strychnos nux-vomica) 

 of the logonia family. Atropine (G17H21NO3) is an alkaloid obtained 

 from the roots and leaves of the belladonna plant (Atropa belladonna) 

 of the nightshade family. It is used in the examination of the eyes. 

 Cocaine (C17H21NO4) is an alkaloid secured from the dried leaves of 

 the coca shrub (Erythroxylon coca) of the coca family. It is used to 

 counteract pain. Aconitine (C33H45NO12) is the active alkaloid prin- 

 ciple derived from the dried tubers of the monkshood plant (Aconitum 

 napellus) of the crowfoot family. It is used as a cardiac and respiratory 

 sedative. 



Certain of our plants poison the skin when they or their products 

 come in contact with it. The following examples are typical: 



Poison ivy (Rhus toxicodendron) of the sumac family produces the 

 well-known effects of itching, and eruption, swelling of the skin of sus- 

 ceptible persons, especially women and children. Poison ivy plants may 

 be distinguished from other viny plants by their white fruits and three 

 leaflets. The poisonous principle is a fixed oil known as cardol. Poison 

 sumac (Rhus vernix) of the sumac family produces itching, eruption, and 

 swelling of the skin of susceptible persons. The active principle is a fixed 

 oil similar to the one in poison ivy if it is not identical. Poison sumac 

 plants can be distinguished from common sumacs by (1) greenish- white 



