Jack Dykinga / Organ Pipe Cactus (Stenocereus thurberi) amongst flowering Brittlebush (Encelia farinosa) and Teddy Bear Cholla (Opuntia bigelovii), with the Ajo Mountains in the background Organ Pipe Cactus National...

Yva Momatiuk & John Eastcott / Organ Pipe Cactus (Stenocereus thurberi) with many stalks, spring evening, during drought year, Organ Pipe Cactus National Monument, Arizona

Jouan Rius / Rainbow over Saguaro cacti (Carnegiea gigantea), Organ Pipe Cactus (Stenocereus thurberi) and Foothills Palo Verde tree (Cercidium microphyllum), Organ Pipe Cactus National Monument, Sonoran Desert, A...

Jouan Rius / Saguaro cacti (Carnegiea gigantea) and Organ Pipe Cactus (Stenocereus thurberi), Organ Pipe Cactus National Monument, Sonora Desert, Arizona, USA. April 2014.

Jouan Rius / Organ pipe cactus (Stenocereus thurberi) with the Ajo Mountains in the background, Organ Pipe Cactus National Monument, Sonora Desert, Arizona, USA

Jack Dykinga / Organ Pipe cactus (Stenocereus thurberi) with Queen's Wreath (Antigonon leptopus) flowers, Rio Mayo drainage, Sonora, Mexico.

Jack Dykinga / Organ Pipe cactus (Stenocereus thurberi) with Queen's Wreath (Antigonon leptopus) flowers, Rio Mayo drainage, Sonora, Mexico.

Cyril Ruoso / White winged doves (Zenaida asiatica) perching on an Organpipe cactus (Stenocereus thurberi) Vizcaino Desert, Baja California, Mexico, May.

Cyril Ruoso / Organpipe cactus (Stenocereus thurberi) in flower, Sea of Cortez in the background, Baja California, Mexico, May.

Tim Fitzharris / Organ Pipe Cactus (Stenocereus thurberi), Ajo Mountains, Organ Pipe Cactus National Monument, Arizona

Cyril Ruoso / Organ Pipe Cactus (Stenocereus thurberi) by night with opened flower, El Vizcaino Biosphere Reserve, Mexico

Cyril Ruoso / Organ Pipe Cactus (Stenocereus thurberi), El Vizcaino Biosphere Reserve, Mexico