Datura, the thorn-apple or jimsonweed, is a genus of coarse plants of the nightshade family bearing large trumpet flowers and spiny seed-pods. It must be stated plainly at the outset that datura is violently poisonous: every part is rich in the tropane alkaloids atropine, hyoscyamine and scopolamine, and it has caused many deaths and severe poisonings among those who mistook it for something safe. This is fact and warning, not folklore. Its powerful and dangerous chemistry is also the reason it became, in several cultures, a plant of ritual and altered states, a use surrounded everywhere by strict ceremony and danger.
One of datura's alkaloids, scopolamine, has a genuine and continuing place in regulated modern medicine, most familiarly in the small transdermal patches worn behind the ear to prevent motion sickness and post-operative nausea, a tightly dosed pharmaceutical product bearing no resemblance in safety to the raw plant, since the effective medical dose is a tiny, precisely measured fraction of what the whole plant delivers. This gap between a carefully calibrated trace of a compound and the same compound taken from an uncontrolled plant is exactly why datura remains so dangerous outside clinical settings, however legitimate the isolated chemical's medical use has become.