More about the Cordon cactus
(excerpt from a web site)
The Cordon cactus strongly resembles the Saguaro cactus of the Sonoran desert in Arizona. At a distance of 20 feet, they look almost identical. Closer up, one can see that the spines are much longer. In fact, the spines can reach 6 inches long. It is believed that maybe the longer spines can attract more morning dew than short spines; the dew then is wicked to the main stalk and the water is absorbed. In this region of extreme dryness, much drier than Arizona, this would be an advanage.
The Cordon is found in dense stands on archeological sites. This phenomona may be due to the fact that the native populations cultivated the Cordon in order to provide an on-going supply of Cordon fruit (food) and Cordon wood (building materials).
The native populations had a very long-term vision of their needs.