Chinese Galls are a type of excrescence produced on the leaves and petioles of the tree Rhus Semialata by an insect which pierces them and lays an egg. When the egg hatches out into a larva, the larva becomes surrounded by the tissue of the developing gall.
This gall or gall nut contains the highest naturally occurring level of Tannin, from 50% to 70%. The galls are harvested and processed to derive the various grades of Tannic Acid, which is used in a wide variety of applications in industries such as Electrostatic Flocking, Inks, Brewing, Wine etc.Tannins should be avoided by those suffering from aneamia, as they hinder the absorption of Iron.