The Huichol name for Ariocarpus retusus is "Tsuwiri" which means "False Peyote". It's said that if you're not properly purified, the spirits will lead you to the False Peyote. Do not eat the False Peyote unless you are seeking madness.
Ariocarpus retusus is extremely slow growing - taking at least 10 years to reach flowering age. The plant pictured is an older specimen.