Genre: Information/Explanation

In their quest for survival , plants have evolved to produce an amazing variety of chemical compounds known as secondary metabolites . These chemicals often serve to deter herbivores , protect against pathogens and neighbors , or mitigate the effects of radiation , among numerous other uses . Interestingly , many of these chemicals react with human bodies in specific ways , ranging from organ failure and death to reactions that inspire lifesaving pharmaceuticals . The following is a list of plants that , amazingly , affect the brains and mental states of the humans who ingest them . Dennis E. Anderson Peyote is a small cactus found only in the Chihuahuan Desert of southern Texas and northern Mexico . The tops of the cactus can be dried to form " mescal buttons , " which are well known for their hallucinogenic effects and contain the alkaloid mescaline , among others . The hallucinatory effects vary greatly among individuals and even for a particular individual from one drug experience to the next . The variations seem to reflect such factors as the mood and personality of the individual and the setting in which the drug is administered . Hallucinations are usually visual , less often auditory . Side effects include nausea and vomiting . Peyote , like most other hallucinogenic drugs , is not considered to be addictive and is reputed by cultists and some observers to promote morality and ethical behavior among the Native Americans who use it ritually . Courtesy of Prairie Plant Systems Grown all over the world , cannabis ( marijuana ) is probably the most-widespread plant with psychoactive properties . Known for its characteristic leaves , the plant is used in religious practices in India and Africa ( and probably elsewhere ) and is sometimes used illicitly in the United States and Europe , though its legal status is changing in many places . The active ingredient , tetrahydrocannabinol ( THC ) , is present in all parts of both the male and female plants but is most concentrated in the flowering tops of the female . These buds are usually dried and crushed and put into pipes or formed into cigarettes ( joints ) for smoking but can also be added to foods and beverages . Psychological effects tend to predominate , with the user commonly experiencing a mild euphoria and alterations in vision and judgment that result in distortions of time and space . Acute intoxication may occasionally induce visual hallucinations , anxiety , depression , paranoid reactions , and psychoses lasting four to six hours . Marijuana's physical effects include reddening of the eyes , dryness of the mouth and throat , moderate increase in rapidity of the heartbeat , tightness of the chest ( if the drug is smoked ) , drowsiness , unsteadiness , and muscular incoordination . Hashish , a more-powerful form of the drug , is made by collecting and drying the plant's resin and is about eight times as strong as the marijuana typically smoked in the United States . Wayne Lukas – Group IV – The National Audubon Society Collection / Photo Researchers Although not well known in the West , betel chewing is a habit of an estimated one-tenth of the world's population , and betel is considered to be the fourth most-common psychoactive drug in the world ( following nicotine , alcohol , and caffeine ) . Betel nuts grow on the areca palm and are cultivated in India , Sri Lanka , Thailand , Malaysia , and the Philippines . For chewing , a betel quid is formed by wrapping a small piece of the areca palm seed ( the betel nut ) in a leaf of the unrelated betel pepper plant , along with a pellet of slaked lime ( calcium hydroxide ) . Betel chewing releases a number of addictive alkaloids that cause sensations of mild euphoria , and regular users often have red-stained teeth and lips . Although it is important in many cultural traditions of southern Asia , betel chewing is linked to a number of serious health problems , including oral and esophageal cancer , and is of growing concern for health officials . Teun Spaans Jimsonweed grows throughout much of North and South America . It is a weedy annual plant with striking white tubular flowers and spiky seed pods . The leaves and seeds contain potent alkaloids ( hyoscamine and hyoscine ) that cause hallucinations . Used ceremonially by a number of indigenous peoples , jimsonweed acts as a deliriant and can produce intense spiritual visions . However , it is highly dangerous , and careless use can easily result in fatalities . Users often report terrifying hallucinations and paranoid delusions under its influence and may experience prolonged side effects such as blurred vision after its use . Many do not try it a second time . W.H. Hodge Coca is a tropical shrub native to certain regions of Peru , Bolivia , and Ecuador . Its leaves contain the alkaloid cocaine and have been chewed for centuries by the Indians of Peru and Bolivia for pleasure or in order to withstand strenuous working conditions , hunger , and thirst . However , the leaves can also be processed into a potent white crystalline powder that is injected , smoked , or otherwise consumed . When ingested in small amounts , cocaine produces feelings of well-being and euphoria along with decreased appetite , relief from fatigue , and increased mental alertness . Cocaine is habit-forming , and , when taken in larger amounts and upon prolonged and repeated use , cocaine produces depression , anxiety , irritability , sleep problems , chronic fatigue , mental confusion , and convulsions . A toxic psychosis can develop involving paranoid delusions and disturbing tactile hallucinations in which users feel insects crawling under their skin . Cocaine abuse , which had been a marginal drug problem throughout much of the 20th century , grew alarmingly in the late 20th century in several countries , and cocaine became responsible for a markedly increased proportion of drug-induced deaths .