Rolf Nussbaumer / Lace Cactus {Echinocereus reichenbachii} flower abstract, Texas, USA

Kevin Schafer / Hedgehog Cactus (Echinocereus sp) blooming, Zion National Park, Utah

Jouan Rius / Claret Cup Cactus in flower (Echinocereus triglochidiatus), Capitol Reef National Park, Utah, USA, April.

Jack Dykinga / Claret Cup cactus (Echinocereus triglochidiatus) and fallen Agave (Agave utahesis) flowers, Grand Canyon-Parashant National Monument, Arizona, USA.

Mark Taylor / Pasacana Tree Cacti (Echinopsis atacamensis), Salar de Uyuni, Bolivia. December 2016.

Rolf Nussbaumer / Claret Cup Cactus (Echinocereus triglochidiatus), flower, Hill Country, Texas, USA. April

Constantinos Petrinos / Cactus (Echinopsis oxygona) introduced species, Mount Hymettus, Kessariani Aesthetic Forest, East-Central Attica, Greece, March.

Constantinos Petrinos / Cactus (Echinopsis oxygona) introduced species, Mount Hymettus, Kessariani Aesthetic Forest, East-Central Attica, Greece, March.

Constantinos Petrinos / Cactus (Echinopsis oxygona) introduced species, Mount Hymettus, Kessariani Aesthetic Forest, East-Central Attica, Greece, March 2015.

Gabriel Rojo / Cactus (Trichocereus candicans) in flower, the flowers of this species only open at night, Lihue Calel National Park, La Pampa, Argentina

Gabriel Rojo / Cactus (Trichocereus candicans) in flower, the flowers of this species only open fully at night, Lihue Calel National Park, La Pampa, Argentina

Cyril Ruoso / Strawberry Cactus (Echinocereus enneacanthus) blooming, southern Texas

Cyril Ruoso / Ladyfinger Cactus (Echinocereus pentalophus) flower, southern Texas

Tim Fitzharris / Hedgehog Cactus (Echinocereus engelmannii) flowering, Arizona

Floris van Breugel / Hedgehog Cactus (Echinocereus) and an Ocotillo (Fouguieria splendens) in the distance with clouds above, Anza Borrego State Park desert, California, USA, April.

Rolf Nussbaumer / Strawberry Hedgehog Cactus (Echinocereus enneacanthus), blooming. Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / Scaled Quail (Callipepla squamata), adult male and Strawberry Hedgehog Cactus (Echinocereus enneacanthus). Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / Strawberry Hedgehog Cactus (Echinocereus enneacanthus), blooming. Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / Scaled Quail (Callipepla squamata), adult male and Strawberry Hedgehog Cactus (Echinocereus enneacanthus). Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / Strawberry Hedgehog Cactus (Echinocereus enneacanthus), blooming. Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / Strawberry Hedgehog Cactus (Echinocereus enneacanthus), blooming. Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / Black Swallowtail Butterfly (Papilio polyxenes) male on Strawberry Hedgehog Cactus (Echinocereus enneacanthus). Laredo, Webb County, Texas, USA, April.

Rolf Nussbaumer / Scaled Quail (Callipepla squamata), adult male and Strawberry Hedgehog Cactus (Echinocereus enneacanthus). Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / White-winged Dove (Zenaida asiatica), adult among Strawberry Hedgehog Cactus (Echinocereus enneacanthus) flowers. Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / Dahlia hedgehog cactus (Echinocereus poselgeri) flowers. Laredo, Webb County, South Texas, USA, April.

Rolf Nussbaumer / Dahlia hedgehog cactus (Echinocereus poselgeri) in flower and Texas Prickly Pear Cactus (Opuntia lindheimeri). Laredo, Webb County, South Texas, USA, April.

Suzi Eszterhas / Lace Hedgehog Cactus (Echinocereus reichenbachii) flower detail showing pistil and stamens, Red Corral Ranch, Texas

John Cancalosi / Hedgehog cactus (Echinocereus) with snow after desert snow storm, Sonoran Desert, Arizona, USA

Rolf Nussbaumer / Nichol's hedgehog cactus (Echinocereus nicholii) South Mountain Park, Phoenix, Arizona, USA, March

Philippe Clement / Golden Hedgehog cactus {Echinocereus nicholii}, Organ Pipe Cactus National Monument, Arizona, USA

Philippe Clement / Golden Hedgehog cactus {Echinocereus nicholii}, Organ Pipe Cactus National Monument, Arizona, USA

Rolf Nussbaumer / Lace Cactus in flower {Echinocereus reichenbachii} Hill Country, Texas, USA

Philippe Clement / Strawberry Hedgehog Cactus {Echinocereus engelmannii}, Organ Pipe Cactus National Monument, Arizona

Philippe Clement / Strawberry Hedgehog Cactus {Echinocereus engelmannii} bud and flower, Organ Pipe Cactus National Monument, Arizona

Jack Dykinga / Hedgehog Cactus (Echinocereus engelmanni) with pink / purple flowers, Teddy Bear Chollas (Opuntia bigelovii) in the distance, Joshua Tree National Park, California

John Cancalosi / Hedgehog Cactus (Echinocereus spp.), Sonoran Desert, Arizona, USA

John Cancalosi / Hedgehog cactus {Echinocereus engelmanni} Sonoran desert, Arizona, USA

Pete Oxford / Hedgehog cactus {Echinocereus englemanni} Anza Borrego NP, California, USA.

Pete Oxford / Hedgehog cactus {Echinocereus sp} Anza Borrego NP, California, USA.

Tom Vezo / Hedgehog cactus in flower {Echinocereus engelmanni] Sonoran desert, Arizona, USA.

Tom Vezo / Hedgehog Cactus (Echinocereus engelmannii) in bloom, Sonoran Desert, Arizona

Tom Vezo / Hedgehog Cactus (Echinocereus engelmannii), Prickly Pear (Opuntia sp), and giant Saguaro (Carnegiea gigantea) cati in Sonoran Desert, Arizona

Jim Brandenburg / Hedgehog Cactus (Echinocereus engelmannii) and Mexican Golden Poppies (Eschscholzia glyptosperma), Organ Pipe Cactus National Monument, Arizona

Patricio Robles Gil / Hedgehog cactus in flower {Echinocereus engelmanni} Chihuahua, Mexico

Tom Vezo / Hedgehog cactus in flower {Echinocereus engelmanni} Arizona, USA

Tom Vezo / Hedgehog cactus in flower {Echinocereus engelmanni} Arizona, USA

Suzi Eszterhas / Lace Hedgehog Cactus (Echinocereus reichenbachii) flower detail showing pistil and stamens, Red Corral Ranch, Texas

Tom Vezo / Goldenrod spider {Misumena vatia} on Strawberry hedgehog cactus flower, Arizona, USA

Claudio Contreras / Rainbow hedgehog cactus (Echinocereus rigidissimus) close up, Los Ojos Ranch, Sonora, Mexico.

Jack Dykinga / Claret cup cactus (Echinocereus triglochidiatus) in flower, Santa Catalina foothills, Sonoran Desert, near Tucson, Arizona, USA. August.

Jack Dykinga / Claret cup cactus (Echinocereus triglochidiatus) in flower, Santa Catalina foothills, Sonoran Desert, near Tucson, Arizona, USA. August.

Jack Dykinga / Ornamental trichocereus cactus (Trichocereus pachanoi) in full bloom after desert monsoon rain, Tucson, Arizona, USA. June.

Jack Dykinga / Ornamental trichocereus cactus (Trichocereus pachanoi) in full bloom after desert monsoon rain, Tucson, Arizona, USA. June.

John Cancalosi / Cactus bees (Diadasia Rinconis) feeding on nectar and collecting pollen from Hedgehog cactus (Echinocereus) flower, Sonoran desert, Arizona, USA.

Gabriel Rojo / Burnt remains of native Cactus (Trichocereus candicans) in the Calden Forest during the summer fires, Lihue Calel National Park, La Pampa province, Argentina. January 2018.

Jack Dykinga / Hedgehog cactus (Echinocereus engelmannii) lying dead amid the dead arms of a Chain chola cactus (Opuntia fulgida). The extended drought is even killing plants that are drought tolerant. Ironwood Fore...

John Shaw / Cordon cacti (Trichocereus pasacana) on Isla Incahuasi (Fish Island), in the midst of the Salar de Uyuni salt flats, Bolivia. March.

John Shaw / Giant Cordon cacti (Echinopsis atacamensis) on Incahuasi Island in Salar de Uyuni salt flats, Bolivia. March.

John Shaw / Giant Cordon cacti (Echinopsis atacamensis) on Incahuasi Island in Salar de Uyuni salt flats, Bolivia. March

Jack Dykinga / Desert gold (Geraea canescens) flowers growing in the over-flow of the rain swollen Armargosa River, Dumont Hills,California, USA.

Jack Dykinga / Trichocereus / Echinopsis cactus flower , native to South America and used as an ornamental plant in dry-land landscaping in Arizona, USA. This blooms for one night only.

Jack Dykinga / Trichocereus / Echinopsis cactus flower, native to South America and used as an ornamental plant in dry-land landscaping in Arizona, USA. This blooms for one night only.

Jack Dykinga / Trichocereus / Echinopsis cactus flowers, native to South America and used as an ornamental plant in dry-land landscaping in Arizona, USA. This blooms for one night only.

Jack Dykinga / Trichocereus / Echinopsis cactus flowers, native to South America and used as an ornamental plant in dry-land landscaping in Arizona, USA. This blooms for one night only.