Lactuca virosa L. - Asteraceae - wild lettuce, bitter lettuce, Giftlattich, Gift-Lattich

Biennial herb, up to 120cm (-2m) high, native from Central Europe to northern Africa, naturalizd in North America, Australia; leaves spatulate, denticulate; flowers yellow.

„L. virosa was used in the 19th century by physicians when opium could not be obtained… A latex which is called lactucarium can be derived from the extract of the stem secretions of Lactuca virosa.“
https://en.wikipedia.org/wiki/Lactuca_virosa

Latucin-15-oxalate, lactucopicrin oxalate, 11,13 dihydro-8-deoxylactucin-15-glycoside (jacquinellin glycoside), lactucopicrin and 8-deoxylactucin 15-oxalate were the main sesquiterpene lactones found in exudates from L.virosa.
[Metabolite Profiling of Sesquiterpene Lactones from Lactuca Species - Major latex components are novel oxalate and sulfate conjugates of lactucin and its derivatives., Sessa, R.A., Bennett, M.H., Lewis, M.J., Mansfield, J.W., Beale, M.H., Journal of Biological Chemistry, Vol.275(35), 2000, 26877-26884]
http://www.jbc.org/content/275/35/26877.full.html

„Lactucin and its derivatives lactucopicrin and 11β,13-dihydrolactucin, which are characteristic bitter sesquiterpene lactones of Lactuca virosa and Cichorium intybus, were evaluated for analgesic and sedative properties in mice. The compounds showed analgesic effects at doses of 15 and 30 mg/kg in the hot plate test similar to that of ibuprofen, used as a standard drug, at a dose of 30 mg/kg. The analgesic activities of the compounds at a dose of 30 mg/kg in the tail-flick test were comparable to that of ibuprofen given at a dose of 60 mg/kg. Lactucopicrin appeared to be the most potent analgetic of the three tested compounds. Lactucin and lactucopicrin, but not 11β,13-dihydrolactucin, also showed sedative properties in the spontaneous locomotor activity test.“
[Analgesic and sedative activities of lactucin and some lactucin-like guaianolides in mice., Wesołowska, A., Nikiforuk, A., Michalska, K., Kisiel, W., Chojnacka-Wójcik, E., Journal of ethnopharmacology, Vol.107(2), 2006, 254-258]

„Safety: Generally thought safe in normal doses, despite a long-standing reputation as a 'legal high'(drug of abuse) and previous use as a mild substitute for opium. No evidence of opioid-like effects has been found in either clinical or pre-clinical studies… May cause allergic reaction in sensitive individuals… wild lettuce toxicity common presentations were mydriasis, dizzyness and anxietyurinary retention, increased bowel sounds and sympathic overactivity…“
[Wild Lettuce Lactuca virosa L., Edwards, S.E., da Costa Rocha, I., Williamson, E.M., Heinrich, M., Phytopharmacy: An Evidence-Based Guide to Herbal Medicinal Products, 2015, 391]

Köhler, F.E., Medizinal Pflanzen, vol. 1: t. 44 (1887) [W. Müller]
http://www.plantillustrations.org/species.php?id_species=581282