Commonly known as Carob, St John's-bread, or Locust bean this tree is native to the Mediterranean.
It is widely cultivated for its edible pods. The ripe, dried pod is often ground to carob powder, which is used to replace cocoa powder. Carob bars, an alternative to chocolate bars, are often available in health-food stores. The production of locust bean gum (LBG), used in the food industry, is the economically most important use of carob seeds. LBG is used as a thickening agent, stabilizer, gelling agent, or as a substitute for gluten in low-calorie products.
The unit "carat", used for weighing precious metal and stones comes from the ancient practice of weighing gold and gemstones against the seeds of the carob tree by people in the Middle East. The system was eventually standardized, and one carat was fixed at 0.2 grams.