Who can argue with Mammalaria compressa, Mammalaria boolii or bombycina, Mammalaria discolor or elongata, Opuntia dejecta --- just to list a few? These Latin names are marvelous! I had a Siamese cat named Opuntia, which suited her perfectly. I also had a cat named Turnip, but we won't go there. These plants, most of whose leaves are reduced to spines, are highly adapted to dry climates. As of January 2018, APG IV places Family Cactaceae in Order Caryophyllales.