Merv Cooper bought in a newspaper article on Luo Han Guo with no English name so George being the whiz he is on computers found the following info on the web by Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon http://www.itmonline.org/arts/luohanguo.htm
Luo Han Guo (luohanguo) refers to the fruit of Siraitia grosvenori, formerly called Momordica grosvenori, a member of the Curcubitaceae. The fruit is well-known for its sweet taste; this plant family (Gourd family) has other members that contain remarkable sweet components, including additional species of the genus Siraitia (e.g., S. siamensis, S. silomaradjae, S. sikkimensis, S. africana, S. borneensis, and S. taiwaniana) and the popular herb jiaogulan (Gynostemma pentaphyllum). The latter herb, which has both sweet and bitter tasting triterpene glycosides in its leaves, is now sold worldwide as a tea and made into an extract for use in numerous health-care products.
Luohanguo has been used as a medicinal herb for treating cough and sore throat and is popularly considered, in southern China, to be a longevity aid. These are the same uses as listed for jiaogulan. Luohanguo has more recently been developed into a non-caloric sweetener to compete with other herbal sweeteners such stevioside from the unrelated Stevia leaf.
Siraitia grosvenorii (syn. Momordica grosvenorii; Thladiantha grosvenorii); also called Arhat Fruit or longevity fruit; is a flowering plant in the Cucurbitaceae, native to southern China. It is the only species in the genus Siraitia and is a herbaceous perennial vine growing to 3-5 m long, climbing over other plants by means of tendrils which twine round stems. The narrow, heart-shaped leaves are 10-20 cm long.
The fruit is globose, 5-7 cm diameter, containing a sweet, fleshy, edible pulp and numerous seeds. The fruit extract is nearly 300 times sweeter than sugar and has been used as a natural sweetener in China for nearly a millennium due its flavour and lack of calories (2,3 kcal per g). It has also been used in traditional Chinese medicine.