Dense white woolly flecks cover the plants body
 

The fruit of A. coahuilense  (left) is pinkish and opens basally, it is very different from the fruit of 
A. myriostigma (right) which is very hairy,  dehisces apically and has a greenish inner colour.
 

Flowers are yellow with a characteristic red heart.

Astrophytum coahuilense with five ribs, has a surprising similarity to A. myriostigma. However, it is different in all characteristics regarding flower, fruit, seed and embryo which looks like in all details to Astrophytum capricorne. The differences into flower, fruit, seed and embryo and flecks are constant and permit in any case to distinguish Astrophytum coahuilense without problems from A. myriostigma.
Nude plants as in the case of Astrophytum myriostigma are unknown.
It looks like the bishop's cap (A. myriostigma), but softer, more grey flecks that cover the plant even more than with the myriostigma.  The flowers are yellow with a characteristic red throat, although can appear pure red or very seldom pure yellow. In the fruit which is red till olive-green coloured and basal opening are up to 200 seeds, similar as in the case of Astrophytum capricorne. This plant is more related to the  Asterias/capricorne group than the myriostigma.
A. coahuilense and A. myriostigma when cross-pollinated are fruitless: they are (usually) sterile by each other.

Cultivation is not too difficult in a greenhouse, although grows quite slowly. The plants need  a loose well-drained  mineral soil. They need a good amount of light. Watering 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 -4° (-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 8-10 cm (20) cm. However, old plants become senile and have a tendency to succumb to disease and a weak root system. At this stage, as is well known, they die suddenly. So, after they reach 10 cm in diameter grow them slowly, and adopt a new repotting period, using intervals of every 2 - 3 years. Additionally grow them under drier conditions or with stronger sunlight. But plants are often grafted to accelerate growth as they would generally take at least a five years 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 more flat to the ground.

Photo of conspecific taxa, varieties, forms and cultivars of A. cohauilense:

• Astrophytum coahuilense
• Astrophytum coahuilense "KIKKO"
• Astrophytum cohauilense "LITTLE FLOWERS"

Below it is possible to see the result of cross pollination between A. asterias and A. coahuilense
 

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Conservation status: Listed in CITES appendix 2.

Origin:  South-western Coahuila and Durante (Ciudad Lerdo, Sierra Baicuco, western Sierra Parras and southern of this line up to the Sierra of El Numero)

Habitat: They inhabit preferentially sunny south and east slopes on lime formations, rarely grow in north or west position between white grey rock in a loose to thick vegetation, which mainly consists of a dry bush community. The soil, consist mainly of lime gravel and sand with isolated humus feedthroughs.

In habitat near Lerdo,  Durango  in association with Hetchia sp. and Thelocactus bicolor
( Photo and © Copyright by Marco Antonio Arroyo - Mexico )

( Photo and © Copyright by Marco Antonio Arroyo - Mexico )
 

A young cultivated specimen 
(SB1474 Lerdo, Durango, Mexico)