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.

Floris van Breugel / Barrel cacti (Ferocactus pilosus) and Ocotillo overlook Palm oasis at sunrise, Anza-Borrego Desert State Park, California, USA March

Floris van Breugel / Ocotillo (Fouquieria splendens) in morning sun, Anza-Borrego State Park, California, USA February

Cyril Ruoso / Verreaux's sifakas (Propithecus verreauxi) in Madagascar ocotillo (Alluaudia procera) trees Berenty, Madagascar.

Neil Lucas / Boojum tree (Fouquieria columnaris) Catavina, Baja, Mexico

Jack Dykinga / Ocotillo cactus (Fouquieria splendens) in desert landscape strewn with rod lava rock, Cabeza Prieta Mountains in the distance, dawn, Cabeza Prieta National Wildlife Refuge, Arizona, USA

Jack Dykinga / Ocotillos (Fouquieria splendens) amongst flowering Mexican Poppies (Eschscholtzia mexicana) on east facing slopes, Sonoran Desert National Monument, Arizona, USA

Jack Dykinga / Boojum tree {Fouquieria columnaris} and Cardon cactus {Pachycereus pringlei} nr Catavina, Desierto Central, Baja California, Mexico

Jack Dykinga / Boojum tree {Fouquieria / Idria columnaris} and Cardon cactus {Pachycereus pringlei} Baja California, Mexico

Jack Dykinga / Boojum tree {Fouquieria / Idria columnaris} and Cardon cactus {Pachycereus pringlei} silhouette at dawn with crescent moon, Catavinia, Baja California, Mexico

Donald M. Jones / Pyrrhuloxia (Cardinalis sinuatus) male feeding on Ocotillo (Fouquieria splendens) flowers, southern Arizona

Tim Fitzharris / Opuntia (Opuntia sp) in Chihuahuan Desert landscape, Big Bend National Park, Texas

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 / Ocotillo (Fouquieria splendens). Sierra de San Francisco, El Vizcaino Biosphere Reserve, Baja California, 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.

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

Jack Dykinga / Teddy bear cholla cactus (Cylindropuntia bigelovii) with Ocotillo (Fouquieria splendens) and flowering Brittlebush (Encelia farinosa) in background. Cabeza Prieta National Wildlife Refuge, Arizona, US...

Jack Dykinga / Teddy bear cholla (Cylindropuntia bigelovii) cacti and Ocotillo (Fouquieria splendens) with flowering Brittlebush (Encelia farinosa) in background, in morning light. Cabeza Prieta National Wildlife Re...

Jack Dykinga / Teddy bear cholla (Cylindropuntia bigelovii) cacti and Ocotillo (Fouquieria splendens) in morning light. Cabeza Prieta National Wildlife Refuge, Arizona, USA. March 2020.

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...

Jack Dykinga / Teddy bear cholla (Cylindropuntia bigelovii) cacti and Ocotillo (Fouquieria splendens) in morning light, flowerin Brittlebush (Encelia farinosa) in background. Cabeza Prieta National Wildlife Refuge,...

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), 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