John Shaw / Desert bighorn sheep ram (Ovis canadensis nelsoni) rubbing against a creosote bush (Larrea tridentata). Valley of Fire State Park, Nevada, USA. February.

Nick Upton / Virgin's Mantle / Cretan prickly clover (Fagonia cretica) a Mediterranean species invasive on the Canary Islands, flowering on a hillside near Ye, Lanzarote, Canary Islands, February.

Jack Dykinga / Caltrops summer poppies (Kallstroemia grandiflora) blooming amid mesquite trees (Prosopis sp.) infront of the Santa Catalina Mountains. July, after summer monsoon rains. Catalina State Park, near Tucs...

Jack Dykinga / Arizona poppies (Kallstroemia grandiflora) blooming amongst Mesquite (Prosopsis sp) trees with Santa Catalina mountains in background. Post summer monsoon rain, evening light. Sonoran Desert, Catalina...

Jack Dykinga / Arizona poppy (Kallstroemia grandiflora) blooming amongst Mesquite (Prosopsis sp) trees with Santa Catalina mountains in background. Post summer monsoon rains, evening light. Sonoran Desert, Catalina...

Eladio Fernandez / Roughbark lignum-vitae (Guaiacum officinale) flowers in Hellshire Hills, Jamaica.

Nick Upton / Sea grape / Uvas de mar (Zygophyllum / Tetraena fontanesii) bushes growing in gulley in volcanic rock cliffs leading down to a beach, La Pared, Fuerteventura, May.

Nick Upton / Spanish sparrow (Passer hispaniolensis) male perched in a Sea grape bush (Zygophyllum fontanesii) in coastal scrubland, Sotavento lagoon, Fuerteventura, Canary Islands, May.

Nick Upton / Sea grape / Uvas de mar (Zygophyllum / Tetraena fontanesii) fruits and leaves, La Pared, Fuerteventura, May.

Jen Guyton / Yellow devil's thorn flower (Tribulus zeyheri) in the Kalahari Desert, South Africa

Jen Guyton / Meerkat (Suricata suricatta) standing among a field of Devil's thorn flowers (Tribulus zeyheri) in the Kalahari Desert, South Africa.

Jen Guyton / Meerkats (Suricata suricatta) two look out over a field of Devil's thorn flowers (Tribulus zeyheri) in the Kalahari Desert, South Africa.