Datura metel is a shrub-like annual (zone 5–7) or short-lived, shrubby perennial (zone 8–10), commonly known in Europe as Indian thornapple, Hindu datura,Grieve, Mrs. M. ed. (introduced by Leyel, Mrs. C.F.) A Modern Herbal first pub. Jonathan Cape, London 1931, reprinted 1974 & 1975. or metel and in the United States as devil's trumpet or angel's trumpet. Datura metel is naturalised in all the warmer countries of the world. It is found notably in India, where it is known by the ancient, Sanskrit-derived, Hindi name dhatūra (धतूरा), from which the genus name Datura is derived.
The plant is cultivated worldwide, both as an ornamental and for its medicinal properties, the latter being due to its tropane alkaloid content. Like its hardier and smaller-flowered relative Datura stramonium, it is now of widespread occurrence, although showing a preference for warmer, humid climates.
Description The plant is an annual or short-lived shrubby perennial herb. The roots are a branched tap root, and are not fleshy like roots found in perennial species such as Datura innoxia and Datura wrightii. The species can grow up to high. The stems are hollow, green or purple-black, somewhat woody, and have a strong odour. It is slightly pubescent, with green to dark violet shoots and oval to broad oval leaves that are often dark violet as well. The leaves are simple, alternate, petiolate, and exhibit entire or deeply lobed margins.
The pleasantly-scented flowers are immensely varied, and can be single or double. Corolla colour can range from white to cream, yellow, red, and violet. The seed capsule is covered with numerous conical warts or short, sparse spines. The fruits break up irregularly at maturity by not dehiscing in four equal valves like those of other Datura species. Seeds are endospermous.Biology Botany Higher secondary second year, Tamil Nadu board Edition - 2008
D. metel was first described by Carl Linnaeus in 1753, but few botanically correct illustrations were made until after the New World was settled. The original home of the plant, although long conjectured to have been India, is now known to have been somewhere in the Americas, probably the Greater Antilles.'Datura (Solanaceae) is a New World Genus' by D.E. Symon and L. Haegi in (page 197 of) Solanaceae III: Taxonomy Chemistry Evolution, Editors J.G. Hawkes, R.N. Lester, M. Nee & N. Estrada, published by The Royal Botanic Gardens Kew, Richmond, Surrey, UK for The Linnean Society of London 1991. . As late as 1992 it was still being claimedSchultes, Richard Evans, Hofmann, Albert and Rätsch, Christian, Plants of the Gods: Their Sacred, Healing, and Hallucinogenic Powers, revised and expanded edition, pub. Healing Arts Press, Rochester, Vermont, 1992 English translation 2001 Page 41. that the plant was "...native probably to the mountainous regions of Pakistan or Afghanistan westward..." While there now remains no doubt that the species originated in the New World, evidence is mounting that it was introduced to the Indian subcontinent - whether by human agency or some chance natural event is not known - at a date no later than the 4th century CE. This precedes the first arrival of European explorers in the Americas.Geeta R and Gharaibeh W 2007 Historical evidence for a pre-Columbian presence of Datura in the Old World and implications for a first-millennium transfer from the New World; J. Biosci. 32 1227–1244.
A wild form of D. metel as a distinct species is unknown. The species, as currently described, is essentially a collection of ancient cultivars likely attributable to pre-Columbian horticultural practices.
Similarities to D. innoxia D. metel is similar, in its above-ground parts, to D. innoxia, but, while D. metel has almost glabrous leaves and fruits that can be nodding or erect and are warty, rather than spiny; D. innoxia is pilose (softly hairy) all over and has a markedly spiny, nodding fruit with a more prominently frilled and reflexed persistent calyx.
Symon and Haegi noted in 1991 the occurrence on Cuba of an apparently wild plant given the name Datura velutinosa V.R. FuentesRevista Jard. Bot. Nac. Univ. Habana 1: 53 1980 publ. 1981. (no longer an accepted species and now listed as a form of D. innoxia), the capsules of which are tuberculate like those of D. metel.Cavazos, M.L., Jiao, M. and Bye, R. Phenetic analysis of Datura section Dutra (Solanaceae)in Mexico, Botanical Journal of the Linnean Society (2000), 133: 493-507.
Historically, single-flowered forms of D. metel have frequently been confused with the widely naturalised D. innoxia - from which it differs in its much less pubescent stems and foliage and shorter-spined and less densely-spined capsules. The reason for this confusion was finally discovered through genetic research carried out in 2000, where it was determined that D. metel is a domesticated form of D. inoxia that was originally derived from Central America and southeastern Mexico.
In support of this claim regarding domestication, Cavazos et al. list several pieces of evidence. While the flowers of wild Datura species are usually white or pale, thin in texture, single and short-lived, the flowers of D. metel have several distinctive strong colour forms, are thick in texture, often have double or triple flowers (trumpet-like corollas nested one within the other) and can last for up to a week before withering. Additionally, the seed capsules of wild Datura species are usually clad with sharp spines which protect them from premature predation, while those of D. metel bear short, sparse spines or tubercles. It is also found that regrowth of the perennial wild species sprouts from the top of the thick roots below ground level, while in D. metel such regrowth is sub-shrubby, sprouting from the woody stem base. It is those woody stems that are used in the vegetative propagation of this 'species' in the indigenous horticulture of southern Mexico. In the light of such evidence, it appears highly likely that humans have in the past undertaken selective breeding of the species ancestral to D. metel to produce mutant forms that flower for longer, have colourful corollas of curious shapes, fruits that lack hurtful spines and somewhat shrubby stems that lend themselves readily to the taking of cuttings.
Cultivars
...it seems clear that D. metel is essentially a collection of cultivars and recent critical authors have found it impossible to recognise a wild type for the species. This view is supported by the tuberculate capsules found in D. metel (as compared with the spinose capsules of other species) and the retention of seeds on the placenta, at least in cultivars 'Fastuosa' and 'Chlorantha'. Both of these traits suggest cultivar selection...The variants of D. metel have been widely grown as ornamentals over a long period of time...There is no evidence that the variants arose from horticultural plant breeding in the Old World...These facts taken together strongly suggest that D. metel was a well-established cultivated species with a range of forms in its place of origin and that these forms arrived ready-made in Europe. A cultivar of D. metel with a glossy, purple-black stem (Hindi: काला धतूरा kāla dhatūra - "black datura") has long existed as a garden plant under the obsolete name Datura fastuosa (coined originally by Linnaeus and featuring the Latin epithet fastuosa, meaning "haughty" or "proud"). Its flowers normally have a double or triple corolla, each corolla having a deep purple exterior and white or off-white interior. The same double or triple corolla is also a feature of the yellow-flowered cultivar 'Chlorantha'. The purple-flowered 'Fastuosa' has been reported to have become naturalised in Israel, where it may yet become as common a roadside weed as the related D innoxia.
D. metel 'Fastuosa' has in recent times become known under a variety of superfluous cultivar names such as 'Black', 'Blackcurrant Swirl', 'Cornucopaea', 'Double Blackcurrant Swirl', 'Double Purple', and 'Purple Hindu'. It has also received many scientific names which should not be used for a cultivar:
Datura hummatu var. fastuosa (L.) Bernh. Datura fastuosa L. Datura metel f. fastuosa (L.) Danert Datura metel var. fastuosa (L.) Saff. Stramonium fastuosum (L.) Moench
Likewise the yellow-flowered D. metel 'Chlorantha' has acquired such superfluous cultivar names as 'Ballerina Yellow'.
Poison
All parts of Datura plants contain dangerous levels of highly poisonous tropane alkaloids meteloidine and its angelate ester and datumetine and may be fatal if ingested by humans or other animals, including livestock and pets. In some places, it is prohibited to buy, sell, or cultivate Datura plants.
Datura metel may be toxic if ingested in a tiny quantity, symptomatically expressed as flushed skin, headaches, hallucinations, and possibly convulsions or even a coma. The principal toxic elements are tropane alkaloids. Ingesting even a single leaf can lead to severe side effects.
Criminal poison in Thuggee The Thugs, gangs of professional robbers and murderers who wandered the roads of central India, would sometimes use preparations of Datura metel to stupefy the rich merchants whom they favoured as victims, before strangling or stabbing them. The English word thug traces its roots to the Hindi ठग (ṭhag), which means 'swindler' or 'deceiver'. Accounts of the Thugs written by early 19th century colonial authors tend to evoke an orientalist fantasy of a bloodthirsty (quintessentially) Hindu cult offering human sacrifices to the goddess Kali, while modern scholars tend to perceive the reality of Thuggee to have been more a matter of criminal activity undertaken for gain by organised groups of disaffected and recently unemployed soldiers of both Hindu and Muslim faith.There were also occasional reports, from the earliest times, of gangs [i.e. criminal gangs active long before the advent of Thuggee] who poisoned their victims with Datura, which was commonly used by many Indian highway robbers to stupefy their victims. It seems to have been used [by the Thugs] only intermittently. One Thug described this technique of using the drug as the tool of "mere novices", implying that an experienced strangler should have no need of such an aid to murder.
Medicinal use Datura metel is one of the 50 fundamental herbs used in traditional Chinese medicine, where it is called yáng jīn huā (洋金花). However, the ingestion of D. metel in any form is dangerous and should be treated with extreme caution. According to Drug & Cosmetic Act 1940 & Rule 1995, Datura metel is banned in India except for use in Ayurvedic medicine. In Aruba, Curaçao, Cuba, and Surinam, Datura metel was used in traditional medicine.
Entheogen Datura Linnaeus...The important narcotic species of the Old World is Datura metel. Early Sanskrit and Chinese writings report a hallucinogen that has been identified with this species, and it was probably D. metel that the Arabian Avicenna mentioned as a drug called jouz-mathel in the eleventh century...The epithet Datura was taken by Linnaeus from the vernacular name dhatura or dutra in India, where knowledge of the intoxicating effects of the plant go back to prehistory...This species, of which there are several rather distinctive types, is indigenous to Asia but now ranges widely in tropical and subtropical Asia, Africa and America.Schultes, Richard Evans; Hofmann, Albert (1979). The Botany and Chemistry of Hallucinogens (2nd ed.) pub. Springfield Illinois: Charles C. Thomas. Pages 283 and 288