A new University of Utah study sequenced 53 specimens of the Lanmaoa bolete genus, the family that includes the prized Yunnan delicacy jian shou qing, and found no gene clusters for psilocybin or ibotenic acid (the active compound in fly agaric, Amanita muscaria).
People in Yunnan, China who eat an undercooked prized bolete called jian shou qing, which translates to "turns blue in the hand," are regularly taken to hospital seeing colourful figures only a few centimetres tall. The figures march, dance, and climb on the furniture, sharpening when the sufferer closes their eyes. Clinicians call the effect Lilliputian hallucination, a term borrowed from Jonathan Swift's 18th-century satire in which the protagonist washes up among a race of tiny people.
A single Yunnan hospital treats more than 100 cases a year, and 96 percent of those who come in report seeing the same diminutive visitors, the local term for which is xiao ren ren, or "little people." The clinical pattern is consistent, the poisoning cluster is regional, and the effect is real, not folklore. The 96 percent figure is among people who sought medical help, not all consumers of the mushroom, so it captures only the most visible end of a recurring food-safety problem.
Now a team has sequenced the responsible species, the University of Utah's Natural History Museum reported in November 2025. The species is Lanmaoa asiatica, a member of the bolete family, the same fleshy-pored group that includes the common porcini. Across 53 specimens collected from Asia, the Americas, and Europe, the team built a phylogeny from 1,515 single-copy orthologous genes, the short, conserved stretches of DNA used to anchor evolutionary comparisons. Every major branch of the resulting family tree has full statistical support. It is the first genus-level resolution for Lanmaoa, a group that was itself only formally described in 2014.
The paper, published in the journal Mycologia, reorganises the genus. Six species were renamed into new combinations, four were identified as new to science, and two were formally described for the first time: Lanmaoa fallax and Lanmaoa carbonilivor. The genus now contains 17 recognised species, ranging from prized edibles to a notorious regional hallucinogen.
The most striking result, according to a June 2026 write-up in psychedelics.co.uk, is what the genome did not contain. The team searched L. asiatica for the biosynthetic gene clusters that produce psilocybin in Psilocybe mushrooms and ibotenic acid in Amanita muscaria, the two known molecular routes to a psychoactive mushroom trip. Neither was there. Earlier chemical work, including compound isolation from the fruiting bodies and blood profiling of poisoned patients, had also failed to identify an active agent. The genomic search and the chemistry together leave the active compound unaccounted for, and the paper's claim is properly limited to "no known psilocybin- or ibotenic-acid-style gene cluster," not a blanket ruling on every possible psychoactive chemistry.
What this means, with appropriate caution, is that L. asiatica is more closely related to the common porcini than to any other known hallucinogenic mushroom, a relationship the University of Utah write-up flags as the framing puzzle of the paper. Whatever produces the Lilliputian effect, if a single molecule does, appears to have evolved independently of the two known psychoactive mushroom families. The new phylogeny supports that hypothesis; it does not prove it. Independent replication and an actual identification of the active compound are still owed before anyone can call this a third family of psychoactive mushrooms.
Lilliputian visions are not confined to Yunnan. Indigenous communities in the Philippines' remote Northern Cordillera collect and consume a wild mushroom called Sedesdem, which local knowledge holds occasionally produces visions of little people, called the "ansisit." The researchers travelled to this community in 2024 and collected samples; DNA sequencing identified Sedesdem as Lanmaoa asiatica, the same species as in Yunnan — the same peculiar hallucinations independently reported across a distant culture, suggesting a shared underlying chemical and neurological basis rather than cultural coincidence. A 3rd-century Chinese Daoist text refers to a "flesh spirit mushroom" that, eaten raw, lets one "see a little person" and "attain transcendence immediately," per the University of Utah first-person account by lead researcher Colin Domnauer; the primary text citation would strengthen this historical thread.
For natural-products chemists, the work names a concrete target. Mouse behavior shifts noticeably when given chemical extracts of L. asiatica compared to controls, and the team is fractionating these extracts to isolate the specific bioactive molecules. A bolete that reliably sends people to hospital seeing tiny figures, and whose genome carries no known psychedelic gene cluster, is a defined search space for whatever compound is doing the work. For public-health authorities in Yunnan, the same genome gives a stable handle on a recurring food-safety event that has, until now, been partly filed as folklore. The family tree is solved. The mystery of what the mushroom actually does to the brain is just beginning.