Osage oranges are members of the mulberry family, meaning that they are not true oranges. The fruit produced by these trees does look like an orange, especially at a distance, but it is inedible. Although their fruit cannot be eaten, Osage orange trees have a number of uses, and they can be found throughout the American South and Midwest. Some garden supply stores sell Osage seedlings, for people who wish to plant these distinctive ornamental trees.
The Osage orange is apparently native to Texas and Arkansas, where the trees have been harvested for their useful timber by native Americans for centuries. The wood of this tree is extremely close-grained and yellowish to orange in color. The close grain and straight growth habit makes the timber very useful for things like bows, fenceposts, and musical instruments, among other applications. In fact, the French referred to the Osage orange as bois d'arc in a reference to the historical use as bow wood, and you sometimes hear Osages called “bodarcs” in a corruption of the original French.
These trees are thorny and deciduous, meaning that they lose their leaves in the cooler winter months. The fruits which they produce are large and heavily wrinkled, reminding some people of the brain. Because the fruits endure after the leaves fall off, you can spot an Osage orange in the fall from quite a distance, thanks to the large, brightly colored fruit. When cut open, the fruit proves to be pulpy, pithy, and slimy, making it totally unappetizing to all but the most desperate squirrels. The odd appearance of the fruit has inspired nicknames such as brainfruit, monkey ball, and monkey brain.
One of the primary historical uses of the Osage orange has been in fencing and livestock control. If a row of the trees is planted close together and kept well-pruned, they will form an impenetrable hedge which acts as a very effective fence. This usage has given the tree alternate names like “hedge apple” and “hedge ball.” The Maclura pomifera, as it is formally known, is still used this way, and it makes a very effective privacy fence as well, as you might imagine.
Some people believe that the fruits of the Osage orange are capable of repelling insects. Studies on the fruit have not born this out, although some aromatic compounds in the fruit may be effective at repelling cockroaches. Despite the fact that the fruits are not effective insect repellents, some people use them in their interior decoration anyway, because the fruits look so weird and interesting.