Plants & Human Affairs - Introduction
Cherries.wmf (7140 bytes) Plants & Human Affairs (BIOL106)  -  Stephen G. Saupe, Ph.D.; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321;;

Psychoactive Plants

I. Definition
    Plants that affect the central nervous system

II. Kinds of psychoactive plants/drugs
    Lewin's classic text, Phantastica: Narcotic and Stimulating Drugs – Their Use and Abuse, published in 1924 (German, 1931 English translation) classified psychoactive plants into five groups: Euphorica – sedatives of mental activity (opium, cocaine); Phantastica – hallucinations, illusions, visions; Inebrientia – primary phase of excitation followed by depression (alcohol); Hypnotica – induce sleep (kava); Excitantia – increase excitation of brain without altering consciousness (coffee, tobacco, betel nuts, cola nuts).  Here we will simplify this classification into three main groups:

  1. Stimulants – excite and enhance mental alertness and physical activity without altering consciousness; reduce fatigue and hunger. Examples: cocaine, caffeine. This group includes Lewin's Excitantia & Euphorica
  2. Depressants (or Narcotics) – dull mental activity; awareness; physical performance. Narcotic is another name for category although it is also applied to any compound that is addictive and illegal. Examples - opium, alcohol, kava. This group includes Lewin's Inebrientia, Hypnotica, and Euphorica.
  3. Hallucinogens (or Psychedelics) – cause changes in mood, space/time perception, visions, illusions. Examples include peyote, marijuana, and LSD. This is equivalent to Lewin's Phantastica.

III. Uses of psychoactive plants

  1. Accidental/unintentional exposure
  2. Recreational use – "enjoyment"; escape from daily grind; increase in leisure time which is accompanied by affluence
  3. Religion – many religious ceremonies involve some sort of psychoactive plant. Shamans typically serve as the "priests" or mediators of the experience. In some cases these plants are thought to actually transport the user to the spirit world, while in others, the plants are just "symbols". It has been suggested that organized religions have their origin in ingestion of psychoactive plants (Ott). This statement is difficult to prove, but the fact that every culture has adopted a ritual inebriant supports this idea.
  4. Rituals – similar to above (i.e., calabar bean ceremony to divine for witches)

IV.  Neurobiology and Psychoactive Plants

V. Opium Poppy (Papaver somniferum)

  1. Native to Middle East/Asia. Traditional areas of cultivation include Afghanistan, India, SE Asia. Now lots produced in Mexico and the Golden Triangle (Burma, Thailand, Laos) and the Golden Crescent (Iran, Pakistan and Afghanistan). No longer grows in the wild. suggested long domesticated.
  2. Opium - derived from the cut immature capsule. Score capsule, return and scrap off exudate, dry, roll in ball. This is the crude opium. Interestingly, poppy seeds (as in muffins, etc) come from this same plant. They contain little alkaloid - but will still register positive in a drug test.
  3. Chemistry. The crude opium has an alkaloid content of ca. 30%. 11% morphine; 15% codeine and about 30 other alkaloids. Morphine - used as a pain killer; extremely effective. Named after Morpheus, the Greek God of dreams. First isolated in 1806 by German chemist. Disadvantage - physiologically addictive. Codeine - cough suppressant. Less addictive than morphine. Heroin is chemically modified from morphine. Heroin is more addictive (6x), produces greater symptoms of euphoria.
  4. Why does opium have effect? Morphine acts on areas of brain involved with pain perception and accompanying anxiety. A general nervous system depressant. Also used for diarrhea and cough suppression.
  5. Biologists were surprised that a plant chemical should have activity until they fed a rat radioactive morphine and found that its binds to specific sites. Have found opiate receptors in brain. Suggests that there must be internal opiates. Have isolated endorphins and enkephalins - have morphine-like activity.
  6. Planting, cultivating, and harvesting done by hand because the plant is fragile and labor is cheap in areas where cultivated.
  7. Preparation: smoked, eaten or drunk. Alcohol extract common (called laudanum). Very popular in 19th century.
  8. Opium Wars (1839-1842) - opium use in China spread. British fueled desire for opium. Supplied opium from plantations in India, etc. In large part because British wanted oriental goods and Chinese didn't want anything from Europe. Demanded silver for goods. Soon flow of silver going into China. British wanted it back. Sold opium. In 1839 Chinese said no more and confiscated stocks. British won (1842) and got various concessions including Hong Kong. Second conflict ca. 10 years later.
  9. Strongly addictive. Withdrawal symptoms.

VI. Marijuana (Cannabis sativa)

A.  Taxonomy
    Cannabaceae- Hemp Family. Includes marijuana and hops. Many common names - reflects long intimate association.  There are 1-3 species, depending upon which taxonomist you believe. Some say one species with three distinct races. Others say 3 species - C. sativa (temperate NA, "rest" of world, lower resin content), C. indica (C. Asian, Indian, strong narcotic properties) and C. ruderalis (Siberia, N. Europe, Siberia). In any case, this is a variable (polymorphic) species.   Native to Central Asia/Near East

B.  Botany
    Grows in temperate areas; annual; up to 18 feet tall (4 ft avg.), palmately compound leaves; dioecious - males and females on separate plants; glandular hairs - found on leaves and female flowers especially; produce active ingredients. native to central Asia.

C.  Chemistry
    Cannabinoids found in the resins. These are the active ingredients. THC is the major one. Over 60 different ones. Content of a plant varies from 0.2 - 6%. The amount of resin varies with strain and environmental conditions.

D.  Actions

  • Smoked or ingested
  • THC fat soluble, therefore no injection
  • LD50 THC (10 gm/kg mice, orally; 100-299 mg/kg mice, IV)
  • Effective dose - 200-250 ug/kg smoke; 300-480 ug/kg ingest
  • Actions/Uses - used in treatment of glaucoma, anti-emetic for cancer patients in chemotherapy

E.  Types of marijuana

  • bhang - dried tops of plant; prepare drink or candy
  • ganja - pistillate flowers, smoked
  • Charas - hashish - purified resin.
  • Sinsemilla - seedless, high yielding strain

F.  Effects - may cause chromosomal damage, interfere with DNA synthesis; mimic hormones (i.e., female like breasts on males), lung damage, impairs learning, short term memory, and reaction time.

G.  History - maybe one of first crops cultivated. It is a triple purpose crop: (a) hallucinogenic/medicinal effects; (b) fiber; (c) seed oil. Used for fiber and medicinal purposes ca. 5000 BC in China.

  • Assassin - derived from 11th century Persian Al-Hasan, a leader of a Muslim sect. Swore to kill all enemies. Became known as hashishins. Presumably worked into a frenzy by Cannabis. made a beverage.
  • Reached US around 1900, esp. among jazz musicians. By 1930's, government warning of uses (Reefer Madness). Resulted in the Federal Marijuana Tax Act of 1937 that controlled legal sale of plant and resulted in elimination from US pharmacopoeia.

VII. Cocaine (Erythroxylum sp.)

  1. Native to Andes, South America.
  2. Varieties of two different species are important commercially (E. coca and E. novogranatense)
  3. Leaves chewed with a little ash (lime) by natives for centuries. Lime (calcium carbonate) releases cocaine from leaves.
  4. Has been used at least 3500 years to prevent hunger and fatigue, as a medicine (relieves symptoms of altitude sickness), and as a nutrient source (rich in calcium, iron, phosphorus, vitamin A, vitamin B2 and E.
  5. May have been cultivated as early as 7000 ybp.
  6. At end of 15th century, Spanish allowed enslaved Indians to chew cuz could get more work out of them.
  7. Chemisty - isolated in 1850's by German chemist. use increased in US toward end of 1900's.
  8. Coca Cola – contains extract of coca (also includes caffeine from cola nuts). Vin mariana, a red wine mixed with coca leaf extract was popular from 1844 – 1913.

VIII. Peyote (Lophophora williamsii)

  1. Cactus native to the American SW (Rio Grande Valley) and central/northern Mexico
  2. also occurs in other cacti
  3. used as early as 2000 ybp
  4. from Aztec peyotl - meaning caterpillar cocoon - refers to white hairy buds
  5. mescal buttons; dose of 4-30 buttons
  6. induces auditory, visual, olfactory and tactile hallucinations
  7. includes a variety of alkaloids and phenylethylamines like mescaline – main active ingredient
  8. mescal - three uses for term: peyote, fermented distilled beverage from the century plant (Agave), mescal bean (Sophora secundiflora) a plant that contains cytisine, a toxic alkaloid that causes nausea, convulsions and hallucinations and was used ceremonially by Native Americans
  9. sacred plant, included in rituals, Used by the North American Church. Supreme Court ruled in 1990 that this was not protected activity. Congress passed Religious Freedom Restoration Act (1993) in response that requires government to demonstrate a need to justify intrusion into a religious practice.


  • Williams, Ted. 1999. Legalize It!. Aubudon. November-December. pp 36 – 48.
  • Stix, Gary. 1998. Herb Remedy. Scientific American. Sept 98. pp 18 – 19.
  • Schultes, Richard Evans, WM Klein, T Plowman, TE Lockwood. 1974. Cannabis: An example of Taxonomic Neglect. Botanical Museum Leaflets 23: 337 – 367.
  • Fackelmann, Kathy. 1993. Marijuana and the brain. Science News 143: 88.
  • Iverson, LL. 2000. The Science of Marijuana. OUP.
  • Anderson, Edward. 1996. Peyote. The Divine Cactus. University of Arizona Press, Tucson. 2nd Edn.
  • Wilson, SM. 1993. Coffee, tea, or opium? Natural History. November, pp 74 – 79.
  • White, P. 1985. The poppy – For good and evil. National Geographic. February. pp 141 – 190.


| Top | PHA Home | PHA Course Materials| SGS Home |

Last updated:  12/04/2008 / � Copyright  by SG Saupe /