Pot: 10 cm.
It is a cactus with initially solitary posture, which can abundantly turn on with time. Its cylindrical stem has many rounded tubercles. This species is one of the most spiny of the genus Mammillaria: from the white areolas come out short and thin white and flat radial spines, which hide almost completely the green of the stem; the central spines are instead longer and more robust, tending to fade towards the black at the apex. Flowering occurs only after the plant has reached 7-8 years and produces campanulate flowers of carmine red color. The monstrous shape of the cactus presents geometric anomalies, for example, sometimes asymmetrical protuberances or absence of thorns, different for each individual exemplar , so much so as to make each of them absolutely unique and for this extremely sought after by collectors.