Ololiuqui is the clearest case in this atlas of a colonial account of a plant's effects being vindicated by chemistry, and it is worth setting out because the usual pattern is the opposite.
For most of the intervening period the Spanish descriptions were treated with suspicion. Nineteenth and early twentieth century commentators doubted that a morning glory seed could produce anything, suspected the friars of exaggerating in order to justify suppression, and in some cases proposed that ololiuqui was really datura misidentified. The seeds were tested and found inactive by researchers who, as it turned out, tested them wrongly or in insufficient quantity.
In 1960 Albert Hofmann identified the active constituents as ergoline alkaloids, principally ergine, closely related to the lysergic acid compounds he had worked on in ergot. The finding was surprising on its own terms, since these alkaloids were known from fungi and their presence in a flowering plant was unexpected, and it is now understood to involve a fungal endophyte living in the seed. The sixteenth century reports turned out to be accurate.
Two lessons follow. Colonial records of indigenous practice are hostile witnesses but are not therefore false, and they are frequently the only record there is. And an absence of demonstrated activity is not evidence of absence, a point directly relevant to the blue lotus, where the chemistry is currently unpersuasive and the iconography is not.