A number of trees belonging to the genus Sterculia in India, particularly Sterculia urens and, Africa, and Australia yield gums in considerable quantity, most of which resemble in their appearance Tragacanth, some of which have remarkable adhesive properties and in some of which the adhesive power is lacking but the swelling power when moistened with water is enormous. These gums have been much used of recent years, frequently under the unqualified name of Tragacanth Compositional analysis of the gum revealed uronic acids to be the major component of the polymer ( 26 mol %). Goond Katira, being rich in rhamnose, galactose, and uronic acids, can be categorized on the basis of its sugar composition as a rhamnogalacturonan type of gum.The difference between the Sterculia gums and true Tragacanth can be readily proved by a distillation test with water and the determination of the acidity which is due to acetic acid.
