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.

Melocactus are recognizable by the large cephalium that develops on mature plants. They are native from Brazil to Southern Mexico, including the Caribbean.

Four genera from the subfamily Opuntioideae, all from the Americas.