Pau d'arco, also known as lapacho, is an evergreen tree that is native to the forests of South America. The tree is also a popular landscaping specimen. In fact, it is the national tree of Paraguay.
For thousands of years, South American natives have used the inner bark of the tree to produce Lapacho tea (also called Taheebo), a traditional beverage favored by the Incas. Although the primary constituent in the bark, lapachol, appears to exert antimicrobial activity, it also demonstrates toxicity in animal models.
Therefore, its internal use should be limited to small, short-term doses with more consideration for the topical applications of this herb.