Pau D'Arco (Tebebuia impetiginosa) is a rain forest tree from South America traditionally used to treat fungal infections.  This include Candida, athlete's foot, and nail fungus.  I got some recently for my dogs when I found on a natural healing web side for pets that it can be used for mild easy infections, especially those caused by fungus.  It also can kill bacteria, so can help those types of infections also.  A recent study found it to be effective against parasite infections.  The Tupi Indians of South America call it tajy which means "to have strength and vigor".  They also use it to treat snake and insect bites.
    Taken internally, it helps lower blood-sugar and is reputed to prevent diabetes in some cases.  It is also used for digestive problems.  Rain forest natives also use it for malaria, anemia, coughs, colds and other respiratory illnesses.  They also use it for arthritis, rheumatism and circulation problems.  It is also taken internally for ulcers, urinary tract infections, constipation and allergies.
If you buy Pau D'Arco, make sure you are getting it from a reputable herb supplier.  Some of the Pau D'Arco capsules sold are made mostly, or entirely, from sawdust collected at lumber mills rather than from the inner bark.

Pau D'Arco also has many non-medicinal uses.  The trees are grown in many South American cities for their beauty.  The wood of the trees is used in building houses, boats and farm tools because it is a very durable wood.