Claudio Contreras / Ocotillo (Fouquieria splendens) and Saguaro (Carnegiea gigantea) at sunset in Sonoran Desert. El Pinacate Biosphere Reserve, northwest Mexico.

Claudio Contreras / Sonoran Desert with Saguaro (Carnegiea gigantea) and Teddy-bear Cholla (Cylindropuntia bigelovii) cactic, alongside Ocotillo (Fouquieria splendens). El Pinacate Biosphere Reserve, Sonoran Desert, nort...

Claudio Contreras / Sonoran Desert on volcanic soil with Teddy-bear cholla (Cylindropuntia bigelovii), Saguaro (Carnegiea gigantea) and ocotillo (Fouquieria splendens). El Tecolote volcano, El Pinacate Biosphere Reserve,...

Claudio Contreras / Boojum tree (Fouquieria columnaris) at night with the Orion Constellation, Sonoran Desert, Valle de los Cirios Biosphere Reserve, Baja California Peninsula, Mexico, March

Claudio Contreras / Boojum tree (Fouquieria columnaris), Sonoran Desert, Valle de los Cirios Biosphere Reserve, Baja California Peninsula, Mexico, March

Claudio Contreras / Boojum tree (Fouquieria columnaris), Valle de los Cirios Biosphere Reserve, Sonoran Desert, Baja California Peninsula, Mexico, May

Doc White / Boojum tree (Fouquieria columnaris), unique to central Baja California, Mexico

Doc White / Boojum tree (Fouquieria columnaris), unique to central Baja California, Mexico

Doc White / Boojum tree (Fouquieria columnaris), unique to central Baja California, Mexico

Cyril Ruoso / Boojum tree (Fouquieria columnaris) at dusk, Vizcaino Desert, Baja California, Mexico, May.

Cyril Ruoso / Boojum tree (Fouquieria columnaris), Elephant cactus (Pachycereus pringlei) and Datilillo (Yucca valida) silhouetted at night, Vizcaino Desert, Baja California, Mexico, May.

Cyril Ruoso / Boojum trees (Fouquieria columnaris) Vizcaino Desert, Baja California, Mexico, May.

Cyril Ruoso / Harris' hawk (Parabuteo unicinctus) on nest in a Boojum tree (Fouquieria columnaris) Vizcaino Desert, Baja California, Mexico, May.

Philippe Clement / Ocotillo {Fouquieria splendens} in bloom and Saguaro cactus {Carnegiea gigantea}, Organ Pipe Cactus National Monument, Arizona, USA

Jack Dykinga / Ocotillo (Fouquieria splendens) and Saguaro (Carnegiea gigantea) cacti silhouetted against a colourful sunset, Cabeza Prieta National Wildlife Reserve, Arizona

Jack Dykinga / Solitary Saguaro cactus (Carnegiea gigantea)surrounded by Ocotillo (Fouquieria splendens) and other desert plants, Sierra Pinacate, Mexico

Tom Vezo / Saguaro (Carnegiea gigantea) cactus, Ocotillo (Fouquieria splendens) Prickly Pear (Opuntia sp) cactus, and Cholla (Opuntia sp) cactus, Sonoran Desert, Tucson, Arizona

Tim Fitzharris / Ocotillo (Fouquieria splendens) Saguaro (Carnegiea gigantea) Greasewood (Sarcobatus sp) and Palo Verde (Parkinsonia sp), Arizona

Tim Fitzharris / Ocotillo (Fouquieria splendens) and Saguaro (Carnegiea gigantea) cacti, Santa Catalina Mountains, Arizona

Claudio Contreras / Ocotillo (Fouquieria splendens), Teddy-bear cholla (Cylindropuntia bigelovii) and Saguaro cactus (Carnegiea gigantea) in volcanic ash field, El Pinacate Biosphere Reserve, Sonoran desert, Mexico.

Jack Dykinga / Notch-leaved phacelia (Phacelia crenulata) flowering beside Ocotillo (Fouquieria splendens) with Saguaro cacti (Carnegiea gigantea) behind, Sonoran Desert National Monument, Arizona, USA, March 2023....

Jeff Foott / Small ballmoss (Tillandsia recurvata) growing on Boojum tree (Fouquieria columnaris) branch. Baja California, Mexico.

Jeff Foott / Small ballmoss (Tillandsia recurvata) growing on Boojum tree (Fouquieria columnaris) branch. Baja California, Mexico.

Jeff Foott / Small ballmoss (Tillandsia recurvata) growing on Boojum tree (Fouquieria columnaris) branch. Baja California, Mexico.

Jeff Foott / Small ballmoss (Tillandsia recurvata) growing on Boojum tree (Fouquieria columnaris). Sonoran Desert, Baja California, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) and Mexican giant cardon (Pachycereus pringlei) in Sonoran Desert. Catavina, Valle de los Cirios Reserve, Baja California, Mexico. 2013.

Jeff Foott / Boojum tree (Fouquieria columnaris) with leaves turning yellow in drought, alongside Mexican giant cardon (Pachycereus pringlei), in Sonoran Desert. Near Bahia de Los Angeles, Baja California, Mexico....

Jeff Foott / Boojum tree (Fouquieria columnaris) with leaves turning yellow in drought. Near Bahia de Los Angeles, Baja California, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) in Sonoran Desert. Near Bahia de Los Angeles, Baja California, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) in Sonoran Desert. Near Bahia de Los Angeles, Baja California, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) and Mexican giant cardon (Pachycereus pringlei) amongst rocks in Sonoran Desert, at sunset. Baja California, Mexico. 2017.

Jeff Foott / Boojum tree (Fouquieria columnaris) with leaves turning yellow in drought, alongside Mexican giant cardon (Pachycereus pringlei), in Sonoran Desert. Near Bahia de Los Angeles, Baja California, Mexico....

Jeff Foott / Boojum tree (Fouquieria columnaris) with leaves turning yellow in drought. Near Bahia de Los Angeles, Baja California, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) plants in Sonoran Desert, leaves turning yellow in drought, hills in background. Near Bahia de Los Angeles, Baja California, Mexico. 2017.

Jeff Foott / Boojum tree (Fouquieria columnaris) in Sonoran Desert. Catavina, Valle de los Cirios Reserve, Baja California, Mexico. 2013.

Jeff Foott / Boojum tree (Fouquieria columnaris) in Sonoran Desert. Near Bahia de Los Angeles, Baja California, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) and Mexican giant cardon (Pachycereus pringlei) amongst rocks in Sonoran Desert. Baja California, Mexico. 2017.

Jeff Foott / Boojum tree (Fouquieria columnaris) and Mexican giant cardon (Pachycereus pringlei) in Sonoran Desert. Baja California, Mexico. 2020.

Jeff Foott / Boojum tree (Fouquieria columnaris) and Mexican giant cardon (Pachycereus pringlei) in Sonoran Desert. Near Bahia de Los Angeles, Baja California, Mexico. 2020.

Jeff Foott / Baja elephant tree (Pachycormus discolor) with leaves turning yellow in drought, next to Boojum tree (Fouquieria columnaris). El Vizcaino Biosphere Reserve, Baja California Sur, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) beside Baja elephant tree (Pachycormus discolor) with leaves turning yellow in drought. El Vizcaino Biosphere Reserve, Baja California Sur, Mexico.

Jeff Foott / Coastal century (Agave shawii), Baja elephant tree (Pachycormus discolor) and Boojum tree (Fouquieria columnaris) in Sonoran Desert. Near Bahia de Los Angeles, Baja California, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) with Menzies' cartilage lichen (Ramalina menziesii) hanging from branches. Near Bahia de Los Angeles, Baja California, Mexico.

Jeff Foott / Boojum tree (Fouquieria columnaris) with Menzies' cartilage lichen (Ramalina menziesii) hanging from branches. Near Bahia de Los Angeles, Baja California, Mexico.

Jeff Foott / Mexican giant cardon cactus (Pachycereus pringlei) and Boojum tree (Fouquieria columnaris) in Sonoran Desert, rainbow in background. Catavina, Valle de los Cirios Reserve, Baja California, Mexico.

Jack Dykinga / Brittlebush (Encelia farinosa) Ocotillo (Fouquieria splendens) and lone Saguaro cactus (Carnegiea gigantea), Sierra Pinacate, Carnege, Mexico.

Jack Dykinga / Sonoran Desert with Saguaro (Carnegiea gigantea), Teddy bear cholla (Cylindropuntia bigelovii), Ocotillo (Fouquieria splendens) and flowering Brittlebush (Encelia farinosa). Cabeza Prieta National Wil...