Tim Edwards / View of Mount Ngauruhoe (volcano). Mount Tongariro NP, New Zealand

Rob Brown / Mount Ngauruhoe, Tongariro National Park, New Zealand

Guy Vickers / Morning clouds shroud Mount Ngauruhoe, Tongariro National Park, New Zealand

Harley Betts / Late winter sunset on Mount Ngauruhoe (2,291 meters), Tongariro National Park, New Zealand

Albert Aanensen / Korikori (Ranunculus insignus) with Mt Ngauruhoe in the background, North Island, New Zealand

Mark Jones / Mt Ruapehu eruption June 1996, dawn on Rangipo Desert as large ash plume drifts over Mt Ngauruhoe, 2291m, Tongariro National Park, New Zealand

Claudio Contreras / Brittlebush (Encelia farinosa) and Emory's rock daisy (Perytile emoryi). El Pinacate Biosphere Reserve, Sonoran Desert, northwest Mexico.

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...

Tim Fitzharris / Saguaro (Carnegiea gigantea) cacti and Brittlebush (Encelia californica) flowers in spring, White Tank Mountains, Arizona

Tim Fitzharris / Saguaro (Carnegiea gigantea) cacti and Brittlebush (Encelia californica) flowers in spring, White Tank Mountains, Arizona

Jack Dykinga / Brittlebush (Encelia farinosa) and Owl's clover (Castilleja exserta) in flower amongst Saguaro cactus (Carnegiea gigantea) studded slopes, Sonoran Desert, Tonto National Monument, Arizona, USA, A...

Jack Dykinga / Brittlebush (Encelia farinosa) and Owl's clover (Castilleja exserta) in flower amongst Saguaro cactus (Carnegiea gigantea) studded slopes, Sonoran Desert, Tonto National Monument, Arizona, USA, A...

Jack Dykinga / Brittlebush (Encelia farinosa) and Owl's clover (Castilleja exserta) in flower amongst Saguaro cactus (Carnegiea gigantea) studded slopes, Sonoran Desert, Tonto National Monument, Arizona, USA, A...

Jack Dykinga / Brittlebush (Encelia farinosa) and Owl's clover (Castilleja exserta) in flower amongst Saguaro cactus (Carnegiea gigantea) studded slopes, Sonoran Desert, Tonto National Monument, Arizona, USA, A...

Jack Dykinga / Globemallow (Sphaeralcea ambigua) in flower with Brittlebush (Encelia farinosa) flowering on hill behind between Saguaro cacti (Carnegiea gigantea) Dripping Springs Mountains, Sonoran Desert, Pinal C...

Jack Dykinga / Ocotillo (Fouquieria splenden) in flower with Brittlebush (Encelia farinosa) in desert near Tule Well, Cabeza Prieta National Wildlife Refuge, Arizona, USA. March.

Jack Dykinga / Hillside of flowering Red owl's clover (Orthocarpus purpurascens) Brittlebush (Encelia farinosa) and Teddy bear cholla (Opuntia bigelovii) Harcuvar Mountains, Arizona, USA.

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