At a cave in Southern California, archaeologists recently found centuries-old bundles of hallucinogenic plants tucked into crevices in the low ceiling, near a painting that may depict a flower from the same plant, called datura. The painted images may have been a visual aid to help people understand the rituals they experienced in the cave.
Chew on this
University of Central Lancashire archaeologist David Robinson and his colleagues describe the bundles of leaves and stems tucked into the domed ceiling of California’s Pinwheel Cave. The five-armed pinwheel that gives the cave its name is painted in red nearby, attended by a bizarre-looking figure with antennae, eyes pointed in different directions, and a long body. Archaeologists have dubbed it the Transmorph, perhaps because it wouldn’t answer to anything else they tried. Based on radiocarbon dates of the bundles, people placed them in the room’s nooks and crannies over several centuries, from about 1530 to 1890.
That matches the age of charcoal from nearby chambers in the cave, where people left behind traces of more mundane activities: cooking meat, grinding seeds and nuts, and making stone projectile points. Whatever rituals happened in Pinwheel Cave, they weren’t hidden away or separate from everyday life.
Using a technique called mass spectrometry, Robinson and his colleagues studied the chemical composition of four of the bundles and found the compounds scopolamine and atropine—the same chemical mixture that’s found in datura. The Chumash people of California call the plant Momay and see it as the embodiment of a supernatural grandmother figure. To the Tübatulabal, it’s Mo mo ht, a man who later transformed into the flowering plant.
Datura can be a deadly poison if you eat too much of it; take in just the right amount, though, and you’ll experience vivid hallucinations and a trance-like state. Under a scanning electron microscope, the plant fibers in 14 of the Pinwheel Cave bundles matched other samples from the genus Datura. (Robinson and his colleagues examined one other bundle, which turned out to contain yucca, an edible desert plant.)
The microscopic examination also revealed that the ends of the bundles had been crushed and matted together, and some even had tooth marks still pressed into them. Clearly, people had chewed on these bundles of datura leaves and stems before tucking them away into nooks and crannies in the chamber. That matches historical descriptions of Chumash and Tübatulabal people occasionally eating parts of the datura plant for other rituals. Sometimes the goal might be to heal a physical wound; other times it could be supernatural protection, help finding a lost object or looking into the future, or an extra burst of strength for a hunt.
And at Pinwheel Cave, it seems that people chewed the datura bundles beneath a painted image of the plant itself.
Under the influence
For the record, when people use a hallucinogen as part of a religious or spiritual ritual (as opposed to just for fun), anthropologists call the substance an entheogen. Datura has been a popular entheogen in a lot of cultures on several continents, including groups of people across what is now the Western United States, from California to Texas. And across the Western US, datura flowers have turned up in several cultures’ artwork, along with images of hawkmoths, which pollinate the hallucinogenic flowers.
Prior to the discovery in Pinwheel Cave, archaeologists hadn’t found any clear evidence that people actually used datura at any of the sites where that artwork was preserved on cave walls or beneath rock shelters. That’s part of what makes the Pinwheel find so interesting. The cave paintings, combined with the datura bundles, suggest that art played a role in some of the rituals in which people used datura for trances and visions.
When a datura bud opens into a flower, its five petals unfold in a spiral that looks almost exactly like the five-armed pinwheel in Pinwheel Cave. And Robinson and colleagues suggest that the Transmorph, with its antennae and its strange bug-like eyes, may actually be a hawkmoth, the insect that does most of the work of pollinating datura plants.
Groups like the Chumash and the Tübatulabal, and their ancestors, had traditional stories to explain why datura had the power to cause visions, but they also understood the more pragmatic realities of the plant’s life cycle.
Of course, pollination is slightly hazardous work when your food of choice is laced with scopolamine. As Robinson and his colleagues explained, the moth “consumes nectar from the datura flower before coming under the influence of its effects, thus exhibiting behavior analogous to those consuming datura in the cave.” In other words, the illustration on the cave ceiling may have served as a visual guide to help people understand how the rituals worked and what they were about to experience.
A story of survival
What’s really important about Pinwheel Cave, however, is what it tells us about resilience. People were living, and practicing datura rituals, at the cave well before the first European colonizers arrived in the area. The evidence suggests that life and ritual at the site continued for several centuries during Spanish colonization, through Mexican rule, and finally incorporation into America. That’s a huge amount of cultural and political upheaval in a fairly short time.
Robinson and his colleagues used portable X-ray fluorescence to study the layers of paint on the ceiling of Pinwheel Cave. They found that the pinwheel—the datura flower, probably—had been repainted and touched up many times over the centuries. Generations of people had maintained it, and generations of people had looked up at it as they chewed bundles of datura and slipped into the world of visions.
PNAS, 2020 DOI: 10.1073/pnas.2014529117 (About DOIs).