Ariocarpus retusus is a species of cactus, from the genus Ariocarpus, found mainly in Mexico. It is one of the largest and fastest-growing species of this genus, known for its slow growth. Despite its slow growth, often taking 10 years to reach flowering age, the retusus is a desirable cactus for cultivation, having attractive flowers and an interesting form. It is also one of the easiest cacti to grow from the genus.