During her visit, the secretary and her team stopped at a location of Yi Zuo Yi Wang, a restaurant chain specialising in dishes from the Yunnan province, where a food blogger on Weibo spotted the top official eating a variety of Chinese dishes.
“When I walked by their table on my way to the washroom, I slowed down to take a glance at the dishes they ordered,” the blogger wrote.
The selection included grilled fish, greens, and jian shou qing mushrooms.
“Our staff said she loved mushrooms very much,” the restaurant wrote on social media. “She ordered four portions of jian shou qing (a Yunnan wild mushroom species). It was an extremely magical day.”
An aide to the secretary confirmed to CNN she dined at the restaurant and ordered the mushrooms.
The mushrooms are thought to potentially be hallucinogenic, Dr Peter Mortimer, a professor at Kunming Institute of Botany who studies the regions mushrooms, told CNN.
“Lanmaoa mushrooms are considered poisonous as they can be hallucinogenic,” he said. “However, scientists have not, as of yet, identified the compounds responsible for causing the hallucinations. It remains a bit of a mystery, and most evidence is anecdotal. I have a friend who mistakenly ate them and hallucinated for three days.”
The Independent has contacted the Treasury Department for comment.
Chinese state media quoted diners praising Ms Yellen for her interest in Chinese cuisine and warning about the impacts of the mushrooms.
“You thought you were walking straight but you just fell sideways,” one person who had eaten a similar dish told the Xinhua state news agency.
The restaurant where the secretary ate was quickly flooded with reservations.
"We received a larger number of inquiries about bookings. We are fully booked for Friday and Saturday," a staff member told the state-owned Global Times.
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