For nearly a century, people living thousands of miles apart have described a bizarre experience after eating certain wild mushrooms: seeing dozens or even hundreds of tiny, brightly dressed human figures moving through the real world.
Now, researchers have identified a mushroom species linked to these unusual visions in China and the Philippines. According to a report published by ScienceDaily, researchers at the University of Utah used DNA sequencing to identify the fungus as Lanmaoa asiatica. However, the chemical responsible for the hallucinations remains unknown.The findings, published in the journal Mycologia, offer new evidence that the remarkably similar experiences reported in different regions may have a biological explanation.
They also reopen a scientific mystery that researchers struggled to solve for decades.
A strange phenomenon reported across continents
The visions are known as Lilliputian hallucinations, a term referring to the perception of miniature people or other tiny figures. The name comes from Lilliput, the fictional land inhabited by tiny people in Jonathan Swift’s novel 'Gulliver’s Travels'.People experiencing these hallucinations have described miniature figures walking across furniture, climbing walls, moving around everyday objects and interacting with their surroundings.
Some accounts describe figures resembling elves or clowns wearing colourful clothing. The visions can appear vivid and convincing, rather than like fleeting images.The scientific investigation dates back to 1934, when Western researchers learnt of reports from Papua New Guinea describing miniature-human visions after people ate wild mushrooms. The phenomenon became known as “mushroom madness”.During the 1950s and 1960s, anthropologists and mushroom specialists investigated the reports and considered several species belonging to the Boletaceae family, which includes bolete mushrooms.
Chemical investigations, however, failed to establish what might be causing the unusual effects.Samples were even examined by Albert Hofmann, the Swiss chemist known for isolating psilocybin and discovering the effects of LSD. Researchers were unable to identify a substance that explained the visions. Some scientists consequently questioned whether the mushrooms were responsible, and investigations largely faded by the end of the 1960s.
Reports from China provide a new clue
The mystery resurfaced in the 1990s, when people in Yunnan province in southwestern China reported similar experiences after eating bolete mushrooms. The mushrooms were known locally as “Jian shou qing”, but identifying the exact species responsible for the hallucinations remained a challenge.The fungus is now known as Lanmaoa asiatica, a mushroom that grows in association with pine trees and is eaten in parts of China.
It is prized for its savoury flavour and sold in markets and restaurants during the mushroom season, generally between June and August.In Yunnan, the unusual effects are familiar enough that diners are warned to wait until the mushroom has been cooked thoroughly. Eating it raw or inadequately cooked has been associated with hallucinations and illness.A further clue emerged in 2024, when Colin Domnauer, a doctoral researcher at the University of Utah, learnt of similar experiences among an Indigenous community in the northern Cordillera region of the Philippines.
People there described a wild edible mushroom called “Sedesdem” that could cause visions of miniature humans.The reports were striking because they resembled accounts from China and Papua New Guinea, despite the geographical distance between the communities.
DNA testing links the Chinese and Philippine mushrooms
Domnauer travelled to Yunnan and the Philippines, interviewed local residents and collected mushroom specimens. Researchers then used DNA sequencing to establish the specimens’ identities and examine their evolutionary relationships.
The analysis found that the mushrooms known as Jian shou qing in China and Sedesdem in the Philippines belonged to the same species, Lanmaoa asiatica. The discovery also extended the known distribution of the species beyond China.The research team attempted to collect specimens in Papua New Guinea, where the earliest reports originated, but unusually dry conditions prevented them from obtaining suitable samples for genetic comparison.This means the historical Papua New Guinea cases remain unconfirmed at the species level. Although people in all three locations have reported similar visions after eating wild mushrooms, DNA evidence has directly linked the Chinese and Philippine specimens to L. asiatica, not the mushroom described in the earliest accounts.The distinction is important: the research has identified a species associated with the phenomenon in two locations, rather than conclusively proving that every historical report involved the same fungus.
The chemical behind the visions remains a mystery
Identifying the mushroom has not yet revealed how it affects the brain. Researchers found no evidence of familiar psychoactive mushroom compounds, including psilocybin, in their investigation. The results suggest that L. asiatica may contain a previously unidentified substance responsible for the distinctive visions.Scientists have not yet isolated or chemically identified that compound, so its effects on the nervous system remain unclear.
The mushroom’s visions also differ from the broader range of experiences commonly associated with psilocybin-containing mushrooms.The researchers hope that identifying the substance could help explain how the brain generates detailed visual experiences. Lilliputian hallucinations are not exclusive to mushroom consumption; they have also been documented in some neurological and medical conditions, including dementia and visual impairment.A consistent biological trigger could therefore offer researchers a way to investigate how these unusual perceptions arise, although any medical application remains speculative.The study also examined the wider diversity of the Lanmaoa genus. Researchers analysed 53 specimens and identified 17 species in the group, including four previously unknown to science. The findings demonstrate how DNA analysis can reveal biological diversity that may have gone unnoticed in specimens already preserved in collections.For now, scientists have made progress on one part of the mystery: identifying the mushroom associated with the tiny-human visions in China and the Philippines. The substance that produces the effect, how it alters perception and whether the same species was responsible for the original Papua New Guinea reports remain open questions.