Siraitia grosvenorii (luo han guo or monk fruit) is a herbaceous perennial vine of the Cucurbitaceae (gourd) family, native to southern China and northern Thailand. The plant is cultivated for its fruit, whose extract is nearly 300 times sweeter than sugar and has been used in China as a low-calorie sweetener for cooling drinks and in traditional Chinese medicine.
The plant's fruit is often called in English language publications luo han guo or lo han kuo (from the Chinese luóhàn guǒ, 罗汉果/羅漢果).
The scientific species name honors Gilbert Hovey Grosvenor, who as president of the National Geographic Society, helped to fund an expedition in the 1930s to find the living plant in China where it was being cultivated.