Tragacanth

thumb|right|250px|Astralagus gummiferTragacanth is a natural gum obtained 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.

Gum tragacanth is a viscous, odorless, tasteless, water-soluble mixture of polysaccharides obtained from sap which is drained from the root of the plant and dried. The gum seeps from the plant in twisted ribbons or flakes which can be powdered. When added to water, tragacanth absorbs water and becomes a gel which can be stirred into a paste. The gum is used used in veg-tanned leatherworking as an edge slicking and burnishing compound and is occasionally used as a stiffener in textiles. It contains an alkaloid that has historically been used as an herbal remedy for such conditions as cough and diarrhea. As a mucilage or paste it has been used as a topical treatment for burns. It is used in pharmaceuticals and foods as an emulsifier, thickener, stabilizer, and texturant additive (code E413). Also, it is the traditional binder used in the making of artist's pastels, as it does not adhere to itself the same way other gums (such as gum arabic) do when dry. Gum Tragacanth is also used to make a paste used in Floral Sugarcraft to create life-like flowers on wires used as decorations for cakes. It makes a paste which dries brittle in the air and can take colorings. It enables the user to get a very fine, delicate finish to their work.

Gum tragacanth is less common in products than other gums, such as gum arabic or guar gum, mostly due to the fact that most tragacanth is grown in Middle Eastern countries which have shaky trade relations with countries where the gum is to be used. Commercial cultivation of tragacanth plants has generally not proved economically worthwhile in the west, since other gums can be used for similar purposes.