Rhubarb originates from the Himalayas and was used as a medical plant in China as far back as c. 4,000 years ago. At that time, however, the main focus was on the underground stem (rhizome) instead of the stalks we harvest today.
Today, rhubarb is cultivated in all temperate climate zones around the world. It is interesting to note that rhubarb is not actually a fruit, but a vegetable. Varieties of rhubarb are generally divided into two rough categories: rhubarb with light-red flesh, a green end of the stalk and mild flavour; and rhubarb with red flesh which is slightly more tart.