When is the origin of Datura in India?

Question

The abstract for this paper on PubMed, Historical evidence for a pre-Columbian presence of Datura in the Old World and implications for a first millennium transfer from the New World says,

Datura (Solanaceae)is a small genus of plants that,for long, was thought to occur naturally in both the New and Old Worlds. However, recent studies indicate that all species in the genus originated in the Americas. This finding has prompted the conclusion that no species of Datura could have been present in the Old World prior to its introduction there by Europeans in the early 16th century CE. Further, the textual evidence traditionally cited in support of a pre-Columbian Old World presence of Datura species is suggested to be due to the misreading of classical Greek and Arabic sources. As a result, botanists generally accept the opinion that Datura species were transferred into the Old World in the post-Columbian period. While the taxonomic and geographic evidence for a New World origin for all the Datura species appears to be well supported, the assertion that Datura species were not known in the Old World prior to the 16th century is based on a limited examination of the pre-Columbian non-Anglo sources. We draw on old Arabic and Indic texts and southern Indian iconographic representations to show that there is conclusive evidence for the pre-Columbian presence of at least one species of Datura in the Old World. Given the systematic evidence for a New World origin of the genus, the most plausible explanation for this presence is a relatively recent but pre-Columbian (probably first millennium CE) transfer of at least one Datura species, D. metel, into the Old World. Because D. metel is a domesticated species with a disjunct distribution,this might represent an instance of human-mediated transport from the New World to the Old World, as in the case of the sweet potato (Ipomoea batatas).

So the possibilities seem to be:

• It's endemic to several continents since time immemorial
• Pre-Columbian transfer by humans to the Old World, "probably" in the first millennium CE
• Post-Columbian transfer by humans to the Old World (well into the second millennium CE)

My question includes:

• How good is the evidence for this thesis? How good is this paper in particular? Do other experts agree or disagree with it?

• Including any other papers as well as this paper, what are the earliest clear/convincing testimonies/evidence for the existence of Datura in the Old World? Is there any chance that it existed in India in the centuries BCE?

Reasons why I'm skeptical include:

• I don't know how to evaluate or search academic/scientific literature, which some other people on this site are said to be good at doing.
• Apparently this paper supposes and/or claims to be evidence for Pre-Columbian trans-oceanic contact which Wikipedia says is "controversial", "debatable", and sometimes called "fringe science"
• I know very little, in general, about the Origin of the (botanical) Species, so I don't have strong preconception about the likelihood that a species might be endemic on both land-masses
• Datura is poisonous and entheogenic, so I presume it should exist in Ayurvedic and/or other historic texts? IMO isn't it likely that many (perhaps all) historians cannot be familiar with all these texts? There's a language problem, i.e. the texts presumably exist in many languages. How well has this paper done a literature search on a millenium's worth of texts over a whole continent, which has who-knows-how-many languages? How confident can they be that whichever antique text they cite identifies Datura and not something else? Has anyone else been able to finesse the whole "historical literature" question using another tool, e.g. archaeology of seeds or something like that?

Answer 1

EDIT... there is good information on wiki: https://en.wikipedia.org/wiki/Datura_metel#America_or_Asia_?_Resolution_of_controversy_over_continent_of_origin

1. How good is the evidence presented in the thesis?

The thesis does not draw upon molecular phylogeny evidence. Like DNA evidence in court, DNA phylogeny is considered to be much more compelling evidence than 1000 year old witness accounts. Most scientific studies to determine when speciation occured is nowdays done by molecular analysis rather than scientific fossil and morphological evidence.

The Abstract presumes that, because there is established Datura in the old world, it must have arrived by human transport. That is an scientifically weak assumption. Datura belongs to the family Solenaceae, i.e. tomatos, potatos, of which most occur in the Americas, of which many occur in the old world i.e. Madrake. It is not an unreasonable assumption, and is not fringe science. Pre-Colombian exchange of DNA is an ongoing field of science: Genome-wide Ancestry Patterns in Rapanui Suggest Pre-European Admixture with Native Americans. Current Biology, 2014 DOI: 10.1016/j.cub.2014.09.057 Old World iconography of Solenaceae: http://www.hort.purdue.edu/newcrop/actahort745.pdf

There are also molecular studies of solenaceae available online.

2. What evidence is there that Datura existed in the old world?

I have searched for you, and have found various phylogenetic studies of Datura species and solenaceae, and have not found any unrefuteable evidence that Datura existed in the old world, save for references to old texts with varying interpretations.

The best study is the phylogeny for natural hybridization of Datura species Systematic Botany, Volume 38, Number 3 which studies the genetics of Jimsonweed, purported to have existed in India in the PubMed paper, but he doesn't report any evidence for the timing of the arrival of Jimsonweed in India.

There are many scientific papers studying history which are more historical conjecture and historical research papers than scientific. http://link.springer.com/article/10.1186%2F2241-5793-21-11#page-1

A quality scientific paper studing the age of the first plants would rely on a clear painting or description from an old source, carbon dating, or DNA, and for the moment, the best evidence for pre-colombian arrival of Datura species is historical conjecture.

If Datura did arrive in Asia, it could have done so by trade in the many hundreds of years that the Behring strait was accessible 14000 years ago, in return journeys from northern California. Guides and adventurers may have done the journey multiple times and brought proofs of the strange plants and animals they encountered in the new world. To prove if and when arrived is difficult using books more than 500 years old.

Answer 2

Attacking this purely from the angle of locating pre-Columbian mentions of any species of datura in the Old World, here's one example.

From page 201 of Ronald M. Davidson's book, Indian Esoteric Buddhism: A Social History of the Tantric Movement:

Moreover, many of the siddha scriptures discuss ointments and drugs, especially those applied to the eyes or feet. The use of the various species of datura (especially datura fastuosa) is particularly evident. Sometimes termed the “crazy datura” (unmattadhattura) or “Śiva's datura,” it was generally employed as a narcotic paste or as wood in a fire ceremony and could be easily absorbed through the skin or the lungs.¹⁰³ The seeds of this powerful narcotic, termed “passion seeds” (candabīja), are the strongest elements and contain the alkaloids hyoscine, hyoscyamine, and atropine in forms that survive burning or boiling. In even moderate doses, datura can render a person virtually immobile with severe belladonna-like hallucinations.

Datura fastuosa is a variety of Datura metel. Davidson's provided reference for the above section reads:

Kṛṣṇayamāri-tantra IV.45, IX.4 (seeds); Sampuṭa, To. 381, fols. 121b5, 128a6; Saṃvarodaya-tantra X.36, XXVII.10–14; Mahākāla-tantra, in Stablein 1976, pp. 169, 267, 275–277; Vajramahābhairava-tantra, in Siklós 1996, p. 83; Guhyasamāja XV.81.

Assuming that the "Krishnayamari-tantra" (which apparently concerns "seeds") is the source of his assertion, I came across the following paper by another academic, Kenichi Kuranishi, in which he notes:

The Kṛṣṇayamāritantra, which is categorized in the Yogottaratantra category, most likely dates to from the ninth to the tenth century.¹ The tantra consists of eighteen chapters.

(The reference discusses the dating in more detail.)

So, if these gentlemen are to be believed, then D. metel was in use in India in the first millennium CE.