Astrophytum coahuilense My Cactus Plants Dense white flecks

Astrophytum coahuilense
Common Name(s): Hat of white bishop, Bishop's Cap, Bishop's Miter, Mitra, Bonete de Obispo
Description: Globular cactus devoid of sting introducing 5 well marked and angled ribs. The epidermis is covered with a flocks very dense (dawned whites) giving a downy and dirty aspect to the plant, what allows him a perfect mimicry with its environment where it becomes confused among calcareous stones (white - grey) between which they grow.
It 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.
Stalk: Globular; then becomes more cylindrical and columnare with age; up to a height of 50cm and diameter of 20-30cm
Ribs: These 5 coasts appear from the stadium of seedling, it is a very stable character. There is only on the old individuals that additional coasts can sometimes appear.
Flowers: become blooming at about 3-4 years. Flowers have the root, as all Astrophytum, in the apex at the root of every new areola. The size of the flower (diameter maxi 9 cm) is intermediate between those of myriostigma and Capricorn. Flowers open during the hottest hours of afternoon. By strong warmth they lasted only one day, at best they will open again the following day. Of yellow color with a red throat (bottom of the flower), it is characteristics of the kind bringing closer to it to the Capricorn. But there are rare cases of entirely yellow flowers. These individuals are chosen in culture to try to preserve this unaccustomed character.
Fruits: The fruit of A. coahuilense is pinkish and opens basally, it is very different from the fruit of A. myriostigma which is very hairy, dehisces apically and has a greenish inner color...

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.
Min Temperature: They are frost hardy to -4° (-10°) C

Propagation Methods: 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.