Fall Cactus Flower

Crotalus says:

Now I remember, Damsel! Devil’s Tongue is Ferocactus latispinus! Both the common name and the botanical name refer to the very broad hooked central spine.

Horse Crippler is well-named. In much of its range, it hides in the grass, and since it is small in size, flattened in shape, and stout of spine, it’s like Nature designed a booby trap for livestock. But once discovered, and dug up and potted, it is a magnificent small barrel cactus with a notorious reputation. And as a potted or garden plant, it is no longer dangerous to livestock. It’s one of my favorite barrels, mostly for its reputation.

You’re right about common names being so different from one area to the next. “Horse Crippler” is sometimes applied to Echinocactus horizonthalonius, and by your example, many names are applied to Ferocactus latispinus. Hence, the need for the scientific nomenclature. If I say “horse crippler”, it could refer to either of the aforementioned Echinocacti, or even Agave lechuguilla in parts of New Mexico. But if I say “Echinocactus texensis”, it narrows everything down to one kind of cactus.