Organ pipe cacti are seen at this national monument in southern Arizona. As you drive the  dirt road, Ajo Mountain Drive, you’ll see hanging chain cholla and it may seem as if there are more saguaro cacti than organ pipe cacti. But look at southern mountain slopes and there will be the organ pipe cacti. My point in visiting this national monument was to see and learn about organ pipe cacti.

There are obvious physical differences as you look at the cacti. What I learned though, while saguaro need a “nurse plant”, one which they grow under for shade from the sun such as mesquite or palo verde tree, organ pipe cacti do not! Organ pipe cacti crave heat, thus no “nurse plant” needed. The heat they get is from daytime heat stored in the rocks surrounding the cactus was they stand in the sun, loving the heat and light, found on southern slopes! I have previously seen saguaro cacti flowers where I live, but will not see the organ pipe cacti lavender-white flowers on this trip. Besides flowering in June and/or July, they only open at night. The lesser long-nosed bats are attracted to them.

I discovered a third cacti here! The senita cactus! An abundance of senita cacti can be found at Senita Basin. It’s a 4 mile drive in what appear to be washes off the South Puerto Blanco Drive. This cactus has been called “old man’s beard” and in touching the top portion of the cactus it does feel like an old man’s beard! I believe this cactus is only seen here and Mexico.