Floris van Breugel / Desert agave (Agave deserti) has skewered a ball of spines shed by neighboring Cholla cactus (Cylindropuntia bigelovii) Anza-Borrego State Park, California, USA March

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...

Jack Dykinga / Teddy Bear Cholla (Opuntia bigelovii) and Saguaro Cacti (Carnegiea gigantea) lit by the afternoon light in the Sand Tank Mountains, Sonoran Desert National Monument, Arizona, USA

Jack Dykinga / Teddy bear cholla cactus {Opuntia bigelovii} growing on volcanic lava flow, Pinacate and Gran Desierto Altar Biosphere Reserve, Sonoran desert, Mexico

Jack Dykinga / Teddy bear cholla cactus {Opuntia bigelovii}, Brittlebush {Encelia farinosa} and Red owl's clover {Orthocarpus purpurascens} flowering on Harcuvar mountains, Arizona, USA with Arrastra mountains in th...

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 / 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,...

Jouan Rius / Superstition mountain and Teddy Bear cholla cactus (Opuntia bigelovii) at sunset, Lost Dutchman State Park, Arizona, USA, April.

Jouan Rius / Teddy Bear cholla cactus (Opuntia bigelovii) flowers, Lost Dutchman State Park, Arizona, USA. April.

Jouan Rius / Teddy Bear cholla cactus (Opuntia bigelovii) flowers, Lost Dutchman State Park, Arizona, USA, April 2014.