This is a very diverse genus, in which really one species is unlike the other, and that is what makes it so much interesting. Mostly ball-shaped, not too big, with prominent spines and big showy flowers that appear all summer long. They live in Mexico, some also in USA. Growing needs are similar to those of Ferocactus, i.e. porous substrate, infrequent watering, a lot of sun and rather cold winter (5–10°C). Although they grow in limestone soils at home, they do not require (but welcome) lime in their potting mix. Greenhouse is not a bad idea.