Ferocactus are fierce cacti from Mexico and Southern USA. Leuchtenbergia consists of a single species, from Mexico.

An easy to grow cactus from Argentina, Southeastern Bolivia, Western Paraguay, Uruguay, and the Southernmost part of Brazil.

Four genera that are all now Eriosyce, from Chile and Peru.

Small to medium cacti from USA and Mexico, often with brilliant flowers.

Five cactus genera from the Southern USA and Northern Mexico.

Mammillaria is one of the larger genera in the Cactus family, and one of the most variable, but only some have hooked spines.

Crest and monstose are mutations of the cellular structure.

A genus of cacti from the dry coastal deserts, particularly the Atacama Desert, of northern Chile.

Ariocarpus is one of the treasures of the world of Cacti, from Central to Northern Mexico and Southern Texas. Obregonia, the artichoke cactus, is a genus of cacti with a single species, from Mexico.

Astrophytum (Bishop's Hat) is a (mostly) star shaped cactus from north/central Mexico and southern Texas, USA.