In the rich plant kingdom of Southwest China's Yunnan province, there is an inconspicuous little herb whose seeds are so small that a dozen can be sewed in 1 square millimeter of soil.

It disappeared for a long time, but when it resurfaced it became a prosperous plant for villagers. The minuscule size of its seeds had threatened its very survival until a dedicated team of agricultural researchers came to the rescue.

Known as flea grass, or Adenosma bracteosa, the plant has a distinctive fragrance and has long been cherished by the Aini people of the Hani ethnic group for its remarkable ability to repel fleas and mosquitoes.

"The cultivation of flea grass has become the second-largest industry in our village. Fifty-one households participated in the planting of this unique herb, covering an area of over 500 mu (33 hectares) in 2025, and extracted 270 kilograms of flea grass essential oil," said Liu Zhifang, head of the flea grass planting cooperative in Daka village, Mengla county, in the Xishuangbanna Dai autonomous prefecture.

Flea grass essential oil has been developed into a line of products designed to repel mosquitoes and relieve itching, and been warmly received by consumers, she said.

In addition, female villagers have been taught how to weave dried flea grass into embroidered sachets which are included in authentic ethnic accessories and ornaments. Liu describes the financial possibilities provided by the plant as "employment right on their doorstep".

In 2025, over 90 households in Mengla county planted around 80 hectares of flea grass, producing an annual yield of 300 metric tons of the grass and boosting their income by more than 1 million yuan ($140,000), according to the county's agriculture and rural affairs bureau.