An herb (Lactuca virosa), also known as Opium Lettuce, which, when smoked or drunk as tea, has a mild sedative effect similar to opium. It is also believed to induce vivid dreaming when smoked right before sleeping. The Hopi tribe collect the sap and ritualistically smoke it for this effect.
The active chemical component is the alkaloid lactucarine. Herbalists use it as an anodyne, sedative, narcotic and cough suppressant.