Use
Tragacanth gum is the air-dried gum obtained from Astragalus
gummifer Labillardie`re and other species of Astragalus grown
principally in Iran, Syria, and Turkey. A low-quality gum is obtained by collecting the natural air-dried exudate from Astragalus
bushes. A higher-grade material is obtained by making incisions in
the trunk and branches of the bush, which are held open with
variously sized wooden pegs. The exudate is left to drain from the
incision and dry naturally in the air before being collected. The size
and position of the wooden wedges determine the physical form of
the exudate, while the drying conditions determine the color of the
gum. After collection, the tragacanth gum is sorted by hand into
various grades, such as ribbons or flakes.