''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 Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

growing from a

taproot A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproot ...

to maximum heights of or more. ''Lactuca quercina'' contains

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 ...

, which is the milky sap (white

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 ...

) that flows through the stem, leaves, and roots of the plant. It is used as a medicinal herb when dried after contact with air. It may be used as medicinal treatments for its anodyne, antispasmodic, digestive, diuretic, hypnotic,

narcotic The term narcotic (, from ancient Greek ναρκῶ ''narkō'', "I make numb") originally referred medically to any psychoactive compound with numbing or paralyzing properties. In the United States, it has since become associated with opiates ...

, 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 ...

properties. Concentrations of lactucarium are low in young plants, but increase in older plants, occurring highest when in blooming period. Sap may be applied to skin in use for treatment of external warts. Although the standard definition of lactucarium requires its production from ''

Lactuca virosa ''Lactuca virosa'' is a plant in the ''Lactuca'' (lettuce) genus, often ingested for its mild analgesic and sedative effects. It is related to common lettuce (''Lactuca sativa, L. sativa''), and is often called wild lettuce, bitter lettuce, lait ...

'', it was recognized that smaller quantities of lactucarium could be produced in a similar way from '' Lactuca sativa'' and '' Lactuca canadensis'' var. ''elongata'', and even that lettuce-opium obtained from '' Lactuca serriola'' or ''Lactuca quercina'' was of superior quality.

References

External links

Photo of ''L. quercina'' in bloom at Centre for Genetic Resources, the Netherlands in 2016
quercina Plants described in 1753 Taxa named by Carl Linnaeus {{Cichorieae-stub