Spines on a Saguaro cactus (Carnegiea gigantea) can grow up to one mm a day. Photo from The Superstitions, Arizona.

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Size: 5000px × 3333px
Photo credit: © McPhoto/Bioquatic Photo / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: amerika, arizona, cactaceae, cacti, cactus, carnegiea, caryophyllales, gigantea, kaktus, saguaro, spine, spines, åler