It's become a bit of an iconic image — a young woman wearing a cactus bikini. The photo dates back to 1940 when the Tucson Sunshine Climate Club dressed some University of Arizona coeds up in cactus apparel as a publicity stunt. Of course, it wouldn't have been called a 'bikini' back then, since that term wasn't yet coined. It was called a "cactus sun suit." The suits were made out of Saguaro and prickly pear cacti.
The photos then spread far and wide, including into Nazi newspapers, where they were offered as examples of American decadence, "a peak of utter lack of taste."
The model in the top photo is Merri Ciochetti.
Life - Apr 7, 1941
Arizona Daily Star - Feb 27, 1945
One more photo from the photoshoot.
San Bernardino Sun - Mar 27, 1940