The genus Ariocarpus has been a subject of much affection and attention by growers and botanists but also has been surrounded by many myths that persist to date.
1. Contrary to popular belief, Ariocarpus do not present any special problems in cultivation. Granted, these plants require a little more attention (or rather neglect) than your average cactus, but there are many others far more difficult to grow. An Ariocarpus, if cared for properly, will grow steadily and flower reliably.
2. Cultural advice like "grow in full sun" and "give at least two hefty waterings in the growing season" (Needham, 1983) may very well explain the descriptive term "living fossils" often applied to Ariocarpus plants. In my Mediterranean climate, Ariocarpus certainly appreciate some shading and require as much water as all other cacti, especially if grown in clay pots.
3. "Ariocarpus are the slowest growing cacti." Well, they are particularly slow in childhood, but a 4 inches (10 cm) A. retusus can be grown in about five years, which beats many other cacti. If you want to experience "slow," try some Aztekium from seed.
4. "The minimum time to grow from seed to flowering size is probably ten years, and may well be twice that" (Weightman, 1991). A. agavoides will eagerly flower at three years from seed, and most species will bloom by the age of five or six years.
5. "Ariocarpus seedlings are exceptionally prone to rot." In my experience, this is not true. In fact, I have come to realize that Ariocarpus seedlings benefit, more so than other cacti seedlings, from a humid closed environment during their first year of growth. This was actually the cornerstone in developing a reliable method for raising it from seed.