Atropa belladonna in the context of "Hyoscyamine"

Brugmansia is a genus of seven species of flowering plants in the nightshade family Solanaceae. They are woody trees or shrubs, with pendulous flowers, and have no spines on their fruit. Their large, fragrant flowers give them their common name of angel's trumpets, adjacent to the nickname devil's trumpets of the closely related genus Datura.

Brugmansia species are among the most toxic of ornamental plants, containing tropane alkaloids of the type also responsible for the toxicity and deliriant effects of both jimsonweed and the infamous deadly nightshade. All seven species are known only in cultivation or as escapees from cultivation, and no wild plants have ever been confirmed. They are therefore listed as Extinct in the Wild by the IUCN Red List, although they are popular ornamental plants and still exist wild outside their native range as introduced species. It is suspected that their extinction in the wild is due to the extinction of some animal which previously dispersed the seeds, with human cultivation having ensured the genus's continued survival.

Deliriants are a subclass of hallucinogen. The term was coined in the early 1980s to distinguish these drugs from psychedelics such as LSD and dissociatives such as ketamine, due to their primary effect of causing delirium, as opposed to the more lucid and less disturbed states produced by other types of hallucinogens, where rational thought is better preserved (including the ability to distinguish hallucinations from reality). The term generally refers to anticholinergic drugs, which are substances that inhibit the function of the neurotransmitter acetylcholine.

Common examples of deliriants include plants of the genera Datura and Brugmansia, both containing scopolamine, as well as higher than recommended dosages of diphenhydramine (Benadryl). A number of plant deliriants such as that of the Solanaceae family, particularly in the Americas, have been used by some indigenous cultures to reach delirious and altered states of consciousness for traditions or rituals, such as rites of passage, divination or communicating with the ancestors. Despite their long history of use, deliriants are the least-studied class of hallucinogens in terms of their behavioral and neurological effects.

Hyoscyameae is an Old World tribe of the subfamily Solanoideae of the flowering plant family Solanaceae. It comprises seven genera: Anisodus, Atropa, Atropanthe, Hyoscyamus, Physochlaina, Przewalskia and Scopolia. The genera Atropanthe and Przewalskia are monotypic, the first being endemic to China and the second to Tibet.

All seven genera of the tribe are poisonous and have a long tradition of use as medicinal plants, being rich in tropane alkaloids with anticholinergic properties. Furthermore, the genera Atropa, Hyoscyamus, Scopolia and Physochlaina have furnished entheogens - the first three in the historical context of European witchcraft and, more specifically, of the flying ointments employed in such practices, while the similar chemistry of the remaining genera points to the potential for entheogenic use. Six of the genera have dry, pyxidial fruits i.e. capsules dehiscing by an operculum and thus resembling a pot with a lid. The fruit of the remaining genus Atropa is a glossy, juicy berry, making Atropa species especially dangerous poisonous plants, since - unlike other Hyoscyameae - their attractive fruits may easily be mistaken for edible berries, particularly by children - as has frequently occurred in the case of Atropa belladonna, the infamous Deadly Nightshade.