Obregonia denegrii, Ariocarpus denegrii, Strombocactus denegrii has a very small geographic range near Ciudad Victoria in the Valley of Jaumave, Tamaulipas, Mexico (extent of occurrence approximatively 2,000 km2, area of occupancy 350 km² and there are no more than five subpopulations, all of them are found in one location). The population consists of less than 5,000 plants, and it continues to decrease due to collecting.
This slow-growing plant isn't always the easiest species to cultivate but can enlarge relatively fast when well grown. It is often seen as a grafted plant but grows very well on its own roots too. Needs a very well-drained mineral substratum with little organic matter (peat, humus). Requires light sun to develop good compact growth and waterings should be rather infrequent, to keep the plant flat shaped and not become excessively elongated and unnatural in appearance. Use Water sparingly from March till October and keep perfectly dry in winter, or when night temperatures remain below 10° C (but some people give this plant a light monthly watering to prevent the drying and shedding of the lower tubercles.) It is hardy to -4°C (or less) for a short period. In the rest period no high atmospheric humidity!! Ensure good ventilation. Propagation: Almost exclusively by seeds. But the seedlings are tiny and very slow growing and at first, they take one or two years to reach the diameter of 3-5 mm!!! Once they have reached 4 years old or more they are relatively easy to grow, the problem is getting them to 4 years old! Than they reach 5 cm of diameter in about 5-6 years and require very careful watering. Plants need about 7-8 years to reach the flowering size. Seedlings are sometimes grafted onto column-shaped cacti to increase their growth speed. Grafting is a much easier way of propagation than sowing