A. kotschoubeyanus var. elephantidens
This is the southern form of the species, the plants are much larger with larger, highly textured, triangulate tubercles, and a deep purple flower with little or no white content.

It is very flat and does in most cases not reach more then only a few centimetres above the ground. Although they can form clumps, often only a small disc of tubercles can be seen flat at the soil surface, however these plants grow a large tap root below the surface of the compost.
 

This species start flowering when still young.

Description: They are geophyte plants that produce small star-shaped rosettes.
Stems: Usually solitary, rarely giving rise to side shoots from old areoles, flattened on top, depressed centrally.
Tubercles:  Deltoid highly textured dark olive green  with no spines and lie flat on the soil surface. They are more long than wide, closely packed and divergent, sharply angled apically.
Areoles: With a central longitudinal areolar groove extending to the tips on the adaxial surfaces of the tubercles, woolly, 1-3 mm wide, 5-10 mm long. 
Root: Each plant has a large turnip-like taproot, which lies below the soil surface and serves for water storage.
Flowers: These plants have a  woolly  crown, from which emerge bright pink-violet flowers up to 2.5-5 cm, 2 times wider than long when fully expanded. Flowers arte diurnal and last for 3 to 4 days.
Blooming time: From mid-September onwards.
Fruits: White or green with lots of seed.

Cultivation  The plants need deep pots to accommodate the napiform unit formed by the stem base and the rootstock , and a loose mineral soil with a well-drained substrate. They need a good amount of light, a place near the roof of the greenhouse helps drying the pot after watering. This can be done weekly during summertime, if the weather is sunny enough, with a little fertilizer added. Kept this way, plants will show a healthy, although slow growth. They are frost hardy to -10°C
Propagation: By seeds, remembering that  seedlings dislike strong light and dry conditions  and need to be repotted frequently. Eventually, as they become mature, they attain a maximum size of 5 to 9 cm. But plants are often grafted to accelerate growth as they would generally take at least a decade to reach maturity on their own, but the grafted plants are typical rather tall growing, compared with plants on their own roots that are usually very flat to the ground.

Conservation status: Listed in CITES appendix I

Original Publication: Anhalonium kotschoubeyanum Lemaire, (1842) [Bas.] Bull. Cercle. Confer. Hort. Dep. Seine.

Synonyms:

• Ariocarpus sulcatus Schumann K. (1894) in Engler & Prantl, Nat. Pflanzenfam. 3, 6a:195

• Roseocactus kotschoubeyanus (Lemaire) A. Berger

Origin: Mexico, This species is widely distributed as a large number of small, isolated populations in a big area extending over 600 km, from central Coahuila in the north to Queretaro in the south, and the species is also found in the states of Zacatecas, San Luis Potosi, Nuevo Leon and Tamaulipas.
 

These plants have a  woolly  crown, from which emerge bright pink-violet flowers up to 2.5-5 cm, 2 times wider than long when fully expanded. Flowers arte diurnal and last for 3 to 4 days.

Photo of conspecific taxa, varieties, forms and cultivars of Lobivia (Echinopsis) pentlandii .
 of plants belonging to the Lobivia... complex (This Taxon has lots of synonyms (like most Lobivia) whit several controversial varieties and subspecies):

• Ariocarpus kotschoubeyanus
• Ariocarpus kotschoubeyanus forma mostruosa
• Ariocarpus kotschoubeyanus var. albiflorus
• Ariocarpus kotschoubeyanus var. elephantidens
• Ariocarpus kotschoubeyanus var. macdowellii
• Ariocarpus kotschoubeyanus var. sladovski