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

Jack Dykinga / Cardon cactus (Pachycereus pringlei) and Biznaga/Barrel cactus (Ferocactus diguetii),growing at the edge of the sea, CONANP protected area.Catalina Island, Sea of Cortez, Baja Sur, Mexico. February 20...

Patricio Robles Gil / Barrel cactus (Ferocactus pilosus) Chihuahuan desert, Mexico

Jack Dykinga / A cluster of flowering Barrel cacti (Ferocactus stainsii) with Yuccas (Yucca sp) in the Eastern extension of the Chihuahuan Desert, Tamaulipas, Mexico

Jack Dykinga / Close-up of two Barrel cacti (Ferocactus acanthodes) in the eastern Chihuahuan Desert, Mexico

Jack Dykinga / Clusters of Barrel Cacti (Ferocactus stainesii) and Yuccas (Yucca sp) with the Sierra Madre in the background, Chihuahuan Desert, Mexico, Central America

Jack Dykinga / Arizona Barrel Cactus (Ferocactus wislizenii) flower in full bloom amid the cactus spines, Saguaro NP, Arizona, USA

Jack Dykinga / Barrel cactus (Ferocactus wislizeni) and Prickly pear (Opuntia sp) charred by Big Horn Fire, a wildfire caused by a lightning strike on 5th June 2020 which burnt for six weeks engulfing 120,000 acres...

Jack Dykinga / Barrel cactus (Ferocactus wislizeni) charred by Big Horn Fire, a wildfire caused by a lightning strike on 5th June 2020 which burnt for six weeks engulfing 120,000 acres of Sonoran Desert. Catalina St...

Jack Dykinga / Barrel cactus (Ferocactus wislizeni) with singed skin and spines burnt off by Big Horn Fire, a wildfire caused by a lightning strike on 5th June 2020 which burnt for six weeks engulfing 120,000 acres...

Jack Dykinga / Barrel cactus (Ferocactus wislizeni) with singed skin and spines burnt off by Big Horn Fire, a wildfire caused by a lightning strike on 5th June 2020 which burnt for six weeks engulfing 120,000 acres...

Jeff Foott / Fire barrel cactus (Ferocactus gracilis) flowering. Mission San Borja road, Baja California, Mexico. March.

Jeff Foott / Fire barrel cactus (Ferocactus gracilis) flowers. Near Bahia de los Angeles, Baja California, Mexico. March.

Jeff Foott / Fire barrel cactus (Ferocactus gracilis). Near Bahia de los Angeles, Baja California, Mexico. March.

Jeff Foott / Fire barrel cactus (Ferocactus gracilis) flowering. Mission San Borja road, Baja California, Mexico. March.

Nick Upton / Saguaro cacti (Carnegiea gigantea), Golden barrel cacti (Echinocactus grusonii) and tall Yucca plants (Yucca guatalmensis), at the Botanicactus Botanic Gardens, Ses Salines, Mallorca, August.

John Cancalosi / Desert vine (Janusia gracilis) with Fishhook barrel Cactus (Ferocactus wislizeni) Sonoran Desert, Arizona, USA. August.

Jack Dykinga / Cottontop cactus (Echinocactus polycephalus) with Tinajas Altas Mountains in background, in morning light. Barry M Goldwater Air Force Range, Arizona, USA. February 2020.

Pascal Kobeh / Golden barrel cactus (Echinocactus grusonii) in the Jardin de Cactus in Guatiza, Lanzarote, Canary Islands.

Nick Upton / Group of Golden Barrel Cacti (Echinocactus grusonii), with dead flowers, a species endemic to Mexico, at the Jardin de Cactus, Lanzarote, Canary Islands, February.

John Cancalosi / Fishhook barrel cactus (Ferocactus wislizeni) flowering. Arizona.

John Cancalosi / Fishhook barrel cactus (Ferocactus wislizeni) flowering. Arizona.

John Cancalosi / Golden barrel cactus (Echinocactus grusonii). Endemic to Mexico.

John Cancalosi / Fishhook barrel cactus (Ferocactus wislizeni), two flowers with bee pollinating. Arizona.

John Cancalosi / Fishhook barrel cactus (Ferocactus wislizeni) flowering besides Prickly pear (Opuntia sp), in desert. Arizona.

Michael Hutchinson / Golden barrel cactus (Echinocactus grusonii) in glasshouse, Kew Gardens, London, England, UK.

Cyril Ruoso / Fishhook barrel cactus (Ferocactus wislizeni) flower, Vizcaino Desert, Baja California, Mexico, May.

Cyril Ruoso / Fishhook barrel cactus (Ferocactus wislizeni) close up of flower, Vizcaino Desert, Baja California, Mexico, May.

Cyril Ruoso / Fishhook barrel cactus (Ferocactus wislizeni) close up of spines, Vizcaino Desert, Baja California, Mexico, May.

Cyril Ruoso / Fishhook barrel cactus (Ferocactus wislizeni) in flower, Vizcaino Desert, Baja California, Mexico, May.

Cyril Ruoso / Fishhook barrel cactus (Ferocactus wislizeni) in flower, Vizcaino Desert, Baja California, Mexico, May.

Chris Mattison / Barrel cacti (Copiapoa columna alba) all orientated to the north to minimise damage by the midday sun. Pan de Azucar National Park, Chile.

Chris Mattison / Barrel cacti (Copiapoa columna alba) all orientated to the north to minimise damage by the midday sun. Pan de Azucar National Park, Chile.

Chris Mattison / Barrel cacti (Copiapoa columna alba) all orientated to the north to minimise damage by the midday sun. Pan de Azucar National Park, Chile.

Chris Mattison / Barrel cacti (Copiapoa columna alba) all orientated to the north to minimise damage by the midday sun. Pan de Azucar National Park, Chile.

Chris Mattison / Barrel cacti (Copiapoa columna alba) Pan de Azucar National Park, Chile.

Floris van Breugel / Sunrise over Death Valley (from Corkscrew Peak) with Cottontop cactus (Echinocactus polycephalus). View extending all the way to Badwater (center left near the horizon), the Mesquite Dunes (right),...

Floris van Breugel / Cotton top cactus (Echinocactus polycephalus) among rocks, Death Valley National Park, California, USA, August.

Chris Mattison / Red Barrel Cactus (Ferocactus pilosus) Joshua Tree National Park, California, USA, May.

Jouan Rius / Cottontop cactus (Echinocactus polycephalus) Valley of Fire State Park, Nevada, USA, January 2013.

Jouan Rius / Fishhook barrel cactus (Ferocactus wislizenii) Saguaro National Park, Arizona, USA, December 2012.

Lynn M Stone / Mojave Rattlesnake (Crotalus scutulatus) by Barrel Cactus (Freocactus sp.) in Sonoran Desert, Mesa, Arizona, USA. Non exclusive

Lynn M Stone / Mojave Rattlesnake (Crotalus scutulatus) by Barrel Cactus (Freocactus sp.) in Sonoran Desert, Mesa, Arizona, USA

Visuals Unlimited / Saguaro Cactus (Carnegiea gigantea) Prickly Pear Cactus, Barrel Cactus, Ocotillo, and Palo Verde at sunrise, Saguaro National Park, Arizona, USA

Pete Oxford / Turk's Cap cactus (Melocactus macracanthos) Slagbaai National Park, Bonaire, Netherlands Antilles, Caribbean

Daniel Heuclin / Arizona Barrel Cactus (Ferocactus wislizenii) in flower. Foothills of Santa Catalina Mountains, Arizona, September.

Daniel Heuclin / Arizona Barrel Cactus (Ferocactus wislizenii) flowers. Foothills of Santa Catalina Mountains, Arizona, September.

Tim Laman / A close-up of Barrel cactus (Ferocactus sp) in flower, Anza-Borrego Desert State Park, California, USA.