XIANGTAN, China — If the residents of this city seem a bit lively on even the hottest days or most frigid nights, check their mouths. That minty scent and cracking sound come from a fragrant pick-me-up that men, women and even children chew from breakfast until bedtime.

The source of their euphoria is “binglang,” the dried fruit of the areca palm, sometimes referred to as betel nut, which sets the nervous system buzzing and warms the body, especially after a large banquet.

“It helps with digestion and sobers you up,” said Xie Shuo, a cellphone repairman who added he consumed 100 pods a day. He smiled to reveal blackened gums and stained teeth, one of the less attractive side effects of chewing the fruit. “I’m addicted to binglang, but I really love it so it’s not a problem,” he said.

That is a sentiment shared by many of Xiangtan’s one million residents, whose fondness for the treat has fueled the city’s prosperity. The city, in Hunan Province, is China’s leading commercial producer of binglang. Its manufacturers import the fresh ingredients, mostly from the island province of Hainan, and sell the dried husks across Hunan — and to a lesser extent elsewhere.