Pau D'Arco is a tree that grows in the wild and forests of South America. Its inner bark is used by the pharmaceutical industry. Pau D'Arco was one of the main herbs used by the Incas. Having observed its effectiveness in a wide range of diseases, they called it "a tree blessed by God". In the four centuries following the Spanish invasion of the Americas, the herb was transported and cultivated in Europe. Pau D'Arco plays a key role in the recovery of many diseases due to its positive effect on the immune system.