''Lactuca virosa'' is a plant in the '' Lactuca'' (lettuce) genus, often ingested for its mild

analgesic An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in s ...

and

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

effects. It is related to common lettuce ('' L. sativa''), and is often called wild lettuce, bitter lettuce, laitue vireuse, opium lettuce, poisonous lettuce, tall lettuce, great lettuce or rakutu-karyumu-so.

Description

''Lactuca virosa'' is biennial, similar to prickly lettuce '' Lactuca serriola'' but taller – it can grow to 200 cm (80 inches or almost 7 feet). It is also stouter, the stem and leaves are more purple flushed, and the leaves are less divided, but more spreading, similarly to '' Mycelis muralis'' but showing more than 5 florets. The

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...

is purple black, without bristles at the tip. The pappus is the same as ''Lactuca serriola''. In the northern hemisphere, it flowers from July until September.

Distribution

Found coastally in

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

, rarely in north-east of Ireland. ''Lactuca virosa'' is widespread across much of central and southern Europe. It can be found locally in the south east and east of

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. In the rest of Great Britain it is very rare, and in Ireland it is absent. It is also found in the

Punjab Punjab (; ; also romanised as Panjāb or Panj-Āb) is a geopolitical, cultural, and historical region in South Asia. It is located in the northwestern part of the Indian subcontinent, comprising areas of modern-day eastern Pakistan and no ...

region of

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

and

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

where it grows in the wild. In North America, it has been documented as introduced in

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

Iowa Iowa ( ) is a U.S. state, state in the upper Midwestern United States, Midwestern region of the United States. It borders the Mississippi River to the east and the Missouri River and Big Sioux River to the west; Wisconsin to the northeast, Ill ...

, and

Washington, DC Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...

, and grows wild in other parts of the continent.

History

''Lactuca virosa'' was used in the 19th century by physicians when opium could not be obtained. It was studied extensively by the Council of the

Pharmaceutical Society of Great Britain The Royal Pharmaceutical Society of Great Britain (RPSGB) existed from its founding as the Pharmaceutical Society of Great Britain in 1841 until 2010. The word "Royal" was added to its name in 1988. It was the statutory regulatory and professional ...

in 1911. They discovered two chemicals responsible for the properties of ''L. virosa'';

lactucopicrin Lactucopicrin (Intybin) is a bitter substance that has a sedative and analgesic effect, acting on the central nervous system. It is a sesquiterpene lactone, and is a component of lactucarium, derived from the plant ''Lactuca virosa'' (wild lettu ...

and

lactucin Lactucin is a bitter substance that forms a white crystalline solid and belongs to the group of sesquiterpene lactones. It is found in some varieties of lettuce and is an ingredient of lactucarium. It is also found in dandelion coffee. It has b ...

. In the United States, the plant experienced a resurgence in popularity in the 1970s. Today the plant is un-scheduled by the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA), meaning it is legal to grow, purchase, and own without prescription or license. "Wild Salad" has long been known in the world of "natural remedies" or "alternative treatments". It is often referred to as the poor man's opium.

Pharmacology

latex Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latices are found in nature, but synthetic latices are common as well. In nature, latex is found as a wikt:milky, milky fluid, which is present in 10% of all floweri ...

which is called

lactucarium Lactucarium is the milky fluid secreted by several species of lettuce, especially ''Lactuca virosa'', usually from the base of the stems. It is known as lettuce opium because of its sedative and analgesic properties. It has also been reported ...

can be derived from the extract of the stem secretions of ''Lactuca virosa''. Oils and extracts can also be produced from ''L. virosa''. These oils and extracts have sedative properties in rodents. Although the standard definition of lactucarium requires its production from ''Lactuca virosa'', it was recognized that smaller quantities of lactucarium could be produced in a similar way from '' Lactuca sativa'' and ''

Lactuca canadensis ''Lactuca canadensis'' is a species of wild lettuce known by the common names Canada lettuce, Canada wild lettuce, and tall lettuce. Its true native range is not clear, but it is considered to be a native of the eastern and central parts of Nort ...

'' var. ''elongata'', and even that lettuce-opium obtained from '' Lactuca serriola'' or ''

Lactuca quercina ''Lactuca quercina'' is a species of wild lettuce native to Europe and Asia. It is an annual or biennial herb in the tribe Cichorieae within the family Asteraceae growing from a taproot to maximum heights of or more. ''Lactuca quercina'' co ...

'' was of superior quality. ''Lactuca virosa'' contains

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

coumarin Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by an unsaturated lactone ring , forming a second six-me ...

s, and ''N''-methyl-β-phenethylamine. A variety of other chemical compounds have been isolated from ''L. virosa''. One of the compounds,

, has been shown to act as an

acetylcholinesterase inhibitor Acetylcholinesterase inhibitors (AChEIs) also often called cholinesterase inhibitors, inhibit the enzyme acetylcholinesterase from breaking down the neurotransmitter acetylcholine into choline and acetate, thereby increasing both the level an ...

''in vitro''.

References

General references

External links

Wild lettuce
Vaults of Erowid
Photo of herbarium specimen at Missouri Botanical Garden
{{Authority control virosa Medicinal plants Entheogens Plants described in 1753 Taxa named by Carl Linnaeus Flora of Europe