This plant, a shrub, has been kinder to man than to some of our domesticated creatures. The territory of Astragalus gummifer is mountainous regions with desertic climates. They are found in Iran and Turkey. These plants defend themselves from predators, not only by their thorns, but also with chemical weapons made up predominantly of alcaloïds. These substances cause locoïsm in cattle and horses. The animal is beset to hallucinations at first, and then to dangerous and uncontrollable manias. The muscles become affected, the animal wanders about as if drunk. It does not feed any longer, becomes lean and skeletal and finally dies. Coming back to the plant, one of its protections against dessication is the storage of water by its sugars-rich mucilage, known as “gum adraganth.” This gum has been used for centuries. The Greek naturalist Theophrastos, who lived in the fourth century BC, mentioned it. It is abundant and a single plant can produce up to fifteen kilograms. Nowadays, Iran remains the leading producer in the world, followed by Turkey. Their predominance stems chiefly from the political woes of Greece during the nineteenth century. Earlier on, the Greek islands were the main producers of gum adraganth. This mix of polysaccharides swells when humidified and forms edible nontoxic pastes which, over the ages, have supplied numerous nutritional and pharmaceutical applications. The characteristic uses, however, were in the fine arts. We owe this plant for production of both watercolors and pastels. In the latter the gum serves as binder for the pigments. Watercolor has a gum adraganth base, while gouache has a gum arabic base. Both also incorporate ten percent acacia honey.
My book, in French, Copal benjoin colophane … , Le Pommier, Paris, 2007, provides more information on the lentisk.