Tragacanth is a natural gum obtaine from the dried sap of several species of Middle Eastern legumes of the genus Astragalus, including A. adscendens, A. gummifer, and A. tragacanthus. Some of these species are known collectively under the common names "goat's thorn" and "locoweed". The gum is sometimes called "shiraz gum , "gum elect" or "gum dragon". The name derives from tragos and akantha, which means in Greek "goat" and "thorn", respectively.Iran is the biggest producer of the best quality of this gum.