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?