One of the most frequently encountered and popular edible species sold in Yunnan is Lanmaoa asiatica. Credit: Colin Domnauer/NHMU.

Every year, hundreds of people in the Yunnan Province of China turn up to the hospital reporting the same thing: they ate a Yunnan bolete and then they saw little people. It’s surprisingly common.

“At a mushroom hot pot restaurant there, the server set a timer for 15 minutes and warned us, ‘Don’t eat it until the timer goes off or you might see little people,'” Colin Domnauer, a doctoral candidate in biology at the University of Utah and the Natural History Museum of Utah, who is studying L. asiatica, told the BBC. “It seems like very common knowledge in the culture there.”

Unsurprisingly, some people don’t listen and they suffer the effects.

But it’s not just people in China. One elder tribesman in Papua New Guinea described the effect, explaining how “he saw tiny people with mushrooms around their faces. They were teasing him, and he was trying to chase them away.”

But here’s where the story gets really interesting. Researchers led by Domnauer just synthesized the mushroom’s genome, and whatever it’s making, it’s doing so via a pathway researchers have never described before. In fact, it doesn’t look like any known hallucinogenic effect.

AI-generated image.

Boletes are fleshy mushrooms with a spongy layer of pores under the cap rather than the gills found on many familiar mushrooms. They grow from the ground in wooded areas, often in partnership with trees, and include prized edible species such as porcini.

In markets in Yunnan, China, reddish boletes are sold as food, not as a drug. Local cooks know them as jian shou qing, often translated as “see-hand-blue” or “turns blue in the hand,” because their flesh stains blue when handled or cut. But it’s more a folk name than a precise scientific label.

One species, now formally known as Lanmaoa asiatica, has become the leading suspect behind the Yunnan “little people” stories. It’s related to ordinary boletes rather than the lineage of classic psilocybin “magic mushrooms,” but its effects, if they truly come from the mushroom itself, don’t fit the known chemistry of any other hallucinogenic drug.

Around half the world’s edible mushrooms are in Yunnan. Credit: Colin Domnauer/NHMU.

The first strange thing is the visions. Hallucinogens do not usually give large numbers of people the same detailed image. Classic psychedelics such as psilocybin or LSD can produce recurring kinds of experiences (patterns, intensified colors, altered bodies, spiritual presences) but the exact content is usually shaped by a person’s mood, expectations, memories and surroundings, what researchers call “set and setting.”

In the case of L. asiatica, however, the reports are oddly specific. Domnauer has described hospital records in Yunnan in which almost all patients reported seeing tiny people or elves. The clinical term is Lilliputian hallucination, after the miniature inhabitants of Gulliver’s Travels.

To study the visions, researchers first had to solve a more basic problem: what mushroom were they actually dealing with? The species belonged to Lanmaoa, a poorly sorted genus of boletes whose boundaries were still blurred. Some names had been carried over from older collections; others rested on mushrooms that looked alike but had never been compared genome by genome.

So, the new study begins not with the hallucinations, but with the family tree. Before researchers could hunt for an unknown chemical, they had to rebuild the taxonomy of Lanmaoa itself.

A Tree For Mushrooms

The team sequenced whole genomes from 53 specimens and built a family tree from 1,515 single-copy orthologous genes — genes shared across the sampled species and useful for comparing deep relationships. The study included 21 type specimens, made six new taxonomic combinations, recognized four species as new to science, and formally described two: Lanmaoa fallax and Lanmaoa carbonilivor. The genus now contains 17 recognized species, though it’s unclear which of these cause the little people hallucinations.

But this is where things turn outright bizarre.

Mushroom markets are scattered throughout the capital city of Kunming, ranging in size from a few street blocks to no less than the largest wild mushroom market in the world, where upwards of 200 species of edible fungi are sold. Credit: Colin Domnauer/NHMU.

Classic psychedelic mushrooms make psilocybin and psilocin. Amanita muscaria, another psychoactive fungus, is known for ibotenic acid. But the University of Utah researchers who carried the study have found no traces of known psychoactive compounds in these species. In fact, the species don’t even have the gene clusters that produce psilocybin or ibotenic acid.

Strikingly, this fits with previous studies.

Previously, chemists isolated and tested compounds from the fruiting body and profiled the blood of poisoned patients. They too found nothing that could account for the visions.

So, what gives?

A New Type of Drug?

That does not prove the mushroom is safe, nor does it identify the active compound. But it does suggest something more unsettling: if L. asiatica (and other related species) are responsible for the visions, they may be using a pathway mycologists (mushroom scientists) have not yet found.

That opens up several possibilities. The visions may be caused by an unknown compound made through a different biochemical route. The active substance may appear only under certain conditions, perhaps changing with age, cooking or digestion. It is also possible that the hallucinations depend on a combination of molecules rather than a single drug-like ingredient.

For now, the strongest conclusion is a negative one: this does not look like an ordinary magic mushroom hiding in bolete clothing. Its effects, if confirmed, point to a different kind of fungal chemistry, and possibly a type of neural pathway we don’t know about yet.

That is why the family tree matters. By rebuilding the genus Lanmaoa, Domnauer and colleagues gave researchers a map for the next stage of the search. They can now ask which species are close to L. asiatica, whether any relatives cause similar symptoms, and whether those species share overlooked genes for unusual chemistry.

The mystery, in other words, has moved from folklore into genomics. The little people of Yunnan are no longer just a strange story about a mushroom. They are a clue pointing toward a possible new lineage of psychoactive fungi.

But the researcher believes we’ve just scratched the surface when it comes to these extraordinary mushrooms.

“I’m fascinated by how far the knowledge of these mushrooms extends, across both space and time. Are there additional cultural traditions and groups surrounding this psychoactive species that have yet to be documented? Does humanity’s knowledge of this mushroom and its most bizarre effects stretch further into history, and deeper into folkloric beliefs, that we currently appreciate? Given the remarkable findings we’ve made in just the past few years, I believe the answer to both these questions is yes.”