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. It looks like the bishop's cap, 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.