Pima County sheriff's Deputy Daniel Jelineo said the black sports car struck the cactus while crossing a median.
The broken-off cactus ended up partially inside the car, with the rest jutting over car's hood.
Jelineo said deputies detained the driver for further investigation after observing signs and symptoms of impairment.
The driver's identity wasn't released.
Firefighters responded to this auto accident this morning at approximately 9:30 AM. Miraculously, no injuries were reported. pic.twitter.com/yOuSYsW2te— Northwest Fire (@NorthwestFire) July 10, 2019