What Is The Name Of This Cactus?
cactus in Arizona--has red needles
Certified GKH Gardening Expert
Pinning down cacti is a monumental task. I will do my best to get you close.
My best guesses will bring you to four Genera (and possibly more) With thousands of species within- Ferocactus, Melocactus, and Echinocactus, and Echinocereus.
This collection of articles will hel you with care of Cacti: https://www.gardeningknowhow.com/category/ornamental/cacti-succulents/scgen