Every year, doctors at a hospital in China's Yunnan Province treat hundreds of people with the same strange complaint. They arrive during the months of June to August, feeling dizzy and disoriented.
Blood tests to assess their liver and kidney function find little untoward, but something is definitely off, because they all say the same thing – that they have seen tiny, elf-like figures prancing around.
The cause of these hallucinations is an earthy-coloured fungus that turns blue when sliced apart. Lanmaoa asiatica is a mushroom that grows in Yunnan, southwest China, and the Cordillera Region of the Philippines.
When people eat it raw or undercooked – as happens every mushroom season – they all report the same bizarre symptom, leading to the fungus’s Chinese nickname of ‘Xiao ren ren’ or the ‘little people’ mushroom.
More than 30 years ago, Chinese researchers analysed 300 cases of people with ‘lilliputian hallucinations’.
The psychiatric term, which is used to describe visions of tiny humans or fantastical figures, is named after the imaginary race of little people who inhabited the island of Lilliput in the fictional novel Gulliver’s Travels.
All of the patients claimed to see little people or animals moving around. “They saw them on their clothes when they were dressing and saw them on their dishes when eating,” researchers wrote in a 1991 paper.
“The hallucinations were even more vivid when their eyes were closed,” and the worst affected “felt that the mountains or buildings surrounding them were pressing down upon them.”
It wasn’t until 2015, however, that the mushroom behind the outbreak was formally named and described. Researchers purchased a sample from a street market in Yunnan, then sequenced its DNA.
They confirmed that L. asiatica was new to science and is more closely related to the common porcini mushroom (Boletus edulis) than it is to any known ‘magic’ mushroom species.
Subsequent studies have so far failed to identify the psychoactive ingredient that causes people to experience such strange, yet consistent, visions, but studies have been performed on mice.
When rodents are given extracts of L. asiatica, they too become hyperactive, then slump into a daze. If they saw Lilliputians, the mice declined to say.
Today, L. asiatica can be found on the menu of many Yunnanese restaurants, where its umami flavour is appreciated and a system has been developed to prepare and serve it safely.
This includes cooking the fungus thoroughly, banning the consumption of alcohol with the meal and sometimes keeping a sample for analysis, just in case.
With the average trip lasting one to three days, and sometimes up to a week, it’s wise to be careful. Colin Domnauer, from the Natural History Museum of Utah, is studying the mushroom and has eaten in places where it’s prepared.
He told BBC Future of an encounter he had at a mushroom hot pot restaurant, where the server set a timer for 15 minutes and then said, “Don’t eat it until the timer goes off, or you might see little people.”
Diners have been warned!
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