Horsetail or also called horsetail (lat. Equiseti Herba) is found today in large parts of the northern hemisphere. It contains valuable silicic acid and flavonoids. Because of the storage of silicic acid, the plant with its rough stems used to be used as a scouring agent. The Latin word equiseti means "horse" and "bristle", referring to the hairs on the back of a horse's neck, which the horsetail strongly resembles.