These rod-like woody remains of the decayed cactus, here beneath the ironwood tree, were useful to the living plant and, after life, they are useful to wildlife and humans.
In life, these rods efficiently transport water from roots to stems where it is stored in large quantities and used sparingly in the desert climate.
The same rods also distribute food, produced by the green stem tissue, throughout the plant. Their great strength supports a heavy plant.
The rods have been used to construct shelters, furniture, walking sticks, and as long poles to harvest the saguaro fruit.