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

Rolf Nussbaumer / Saguaro NP, Arizona, with Saguaro cactus + Silver cholla.

Michio Hoshino / Galapagos Land Iguana (Conolophus subcristatus) and Prickly Pear (Opuntia sp) cactus, Galapagos Islands, Ecuador

Claudio Contreras / Sonoran Desert with Teddy-bear cholla (Cylindropuntia bigelovii), Saguaro (Carnegiea gigantea) and Brittlebush (Encelia farinosa). El Colorado volcano in background. El Pinacate Biosphere Reserve, nor...

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 / Teddy-bear cholla (Cylindropuntia bigelovii) in El Elegante volcano crater. El Pinacate Biosphere Reserve, northwest Mexico.

Claudio Contreras / Jumping cholla (Cylindropuntia fulgida) cactus branches hanging down, view of Sonoran Desert and Montezuma's Head Mountain and the Ajo Range. Organ Pipe Cactus National Monument, Arizona, USA. Jan...

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,...

Jack Dykinga / Silver cholla (Cylindropuntia echinocarpa) surrounded by California poppies (Eschscholzia californica) and phacelia. Joshua Tree National Park, Mojave Desert, California, USA. 27th March 2019.

Tim Fitzharris / Teddy Bear Cholla (Cylindropuntia bigelovii) cacti, Crater Range, Arizona

Claudio Contreras / Jumping cholla (Cylindropuntia fulgida fulgida), Rasa Island Special Biosphere Reserve, Sea of Cortez (Gulf of California), Mexico, April

Jouan Rius / Chain-fruit or Jumping cholla (Cylindropuntia fulgida), Organ Pipe Cactus National Monument, Sonoran Desert, Arizona, USA, April.