PRESTON, ENGLAND—According to a Live Science report, researchers led by David Robinson of the University of Central Lancashire have found evidence that the Chumash people ingested hallucinogens at a rock art site in California some 400 years ago. Known as Pinwheel Cave, the rock art features an image of a pinwheel and a moth drawn with ochre. Examination of quids recovered from the cave ceiling with 3-D digital microscopy revealed that the lumps of matted plant fibers had indentations likely to have been made by chewing. Chemical analysis showed that the quids contained the hallucinogenic compounds atropine and scopolamine, which are produced by Datura, a plant also known as jimsonweed and angel trumpet. The pinwheel-shaped flower is twisted up during the day, but it unfurls at dusk and dawn for visiting insects such as the hawk moth, which is known for “loopy” flight after ingesting Datura nectar. The scientists then viewed the quids through a scanning electron microscope, and identified all of the quids but one as Datura flowers. The rock art, Robinson explained, probably “set the scene” for the shared tradition of taking the hallucinogen in the cave. Read the original scholarly article about this research in Proceedings of the National Academy of Sciences. To read about a 1,000-year-old bundle unearthed in Bolivia that contained psychotropic substances, go to "Half in the Bag."