Pau d'Arco is known to have been used by the Incas and other Indigenous peoples of the Amazon as part of their herbal traditions. The Portugese name Pau d'Arco (bow wood) refers to the tree's other historical use of making bows - it's also known as lapacho or taheebo. This is a stately, full leaved canopy tree that grows up to 90 feet tall.
Western herbalism has only become aware of Pau d"Arco in the last 70 years or so, and it's now among the most important herbs we use. It makes a fine tea warm or iced, or can be powdered and eaten directly, or made into tincture.