Although quite common throughout all of northern Mexico, what has come to be called the elephant tree grows only in isolated areas of the American Southwest and West. In fact, the tree's whereabouts were known only to adventurous prospectors and other desert rats until the early 1900s.
Then, a wandering scientist heard a tale concerning a strange white-barked tree with limbs like an elephant's trunk and wood that bled red when cut. Determined to find this tree, the scientist set out into the desert of eastern San Diego County, California. Near a place called Split Mountain, he came upon the tree just as described. It wasn't until the late 1930s, though, that enough trees were found to credit Busera microphylla as native to the U.S. Today, the elephant tree's range is known to extend along the coast of the Gulf of California in Mexico, north to Arizona's Gila Desert, and into the Imperial Valley of California. The largest specimens in the United States 20' tall grow in Arizona.
Called toronto or copal in Mexico, the strangely attractive trees yield a gum that is used there as a base for varnish and a preservative for wood. The gum also works as an adhesive. And the incense burned in Mexican churches has its source in the wood of the elephant tree, a member of the same botanical family that provided the frankincense mentioned in the Bible.