OCOTILLO (Fourquieria splendens)
Other names: none known
Ocotillo is a many stemmed desert plant found in southern Arizona. It is not a tree nor a cactus. The "wood" is quite hard, the stems stool out near the ground, are about an inch in diameter, and are thorny. The "trunk" may be up to 5" or 6" in diameter and 10" long before branching out. When dead or uprooted the ocotillo stems remain attached to the trunk 'for several years before breaking apart.
This writer has found original ocotillo "bearing trees" marked near the turn of the century. They were blazed just barely above the ground and marked "BT" only. There wasn't room for any other marks. The marks were weathered but legible.
Often times the ocotillo is the only thing available to mark as a corner accessory. In this case use it. Blazing is difficult. Use a sharp hatchet and make a small blaze. Mark it BT only with letters as small as possible. Painting wouldn't be of much use but certainly wouldn't hurt anything either.