The black walnut tree is well known and loved for its dark hardwood, but herbalists also love it for the rind of the fruit, also called the hull. The hull of black walnut is used both internally and externally, and can often be found in natural shampoos and scalp rinses. Used by some Native American tribes as both a food and a traditional remedy, colonial Americans also found it useful during the Revolutionary War to combat the malaise that stagnated and lingered in camps.