The saguaro cactus is the most recognized plant of the Sonoran Desert. Growing in cactus forests and towering up to between 40-60-feet. Awesome! No less memorable is the organ pipe cactus Stenocereus thurberi which is the name sake of the Organ Pipe National Monument in southern Arizona. A columnar cactus like the saguaro, the organ pipe cactus grows with numerous branches stemming from a common root crown. They can grow to heights between 16 – 26-feet depending upon growing conditions
Organ pipe cactuses are common south of Ajo and into the Mexican state of Sonora. Like the saguaro it produces a delicious edible fruit, pitahaya in the summer. People and wildlife rely upon this delicacy.
The Sonoran Desert National Monument has several organ pipe cactuses and they are considered to be the northern most specimens known. The organ pipe cactus is not as cold tolerant as the saguaro cactus and the low temperatures typical of Arizona north of Interstate 8 are generally too cold for this species, Organ pipe cactuses can grow in Phoenix if special precautions are taken. At the Desert Botanical Gardens in Phoenix horticulturists cover the tops of the organ pipe specimens under their care with Styrofoam cups to protect the apical meristem or growing tip from frost damage.
The northern most specimen is found in the Sand Tank Mountains just north of Interstate 8 and approximately 8-miles east of Gila Bend. Gila Bend locals call this part of the Sand Tank Mountains the La Nayas after a family who lived in the area. Located on a south facing slope where winter low temperatures are slightly higher than on north facing slopes you can find the northern most specimen recorded. This specimen has 38-arms and is about 20-feet high.
Several organ pipe cactuses are found on the southern slope of Javelina Mountain in the SDNM south of Interstate 8.