Mammillaria dioica possesses short, firm tubercles ending in the spines. Most of these spines are whitish and straight, but each tubercle has a longer central spine which is slightly curved and dark.
A single plant can bear both male and female flowers, from mid-spring to mid-summer. Some plants may produce bisexual flowers as well, thus totaling three types of flower on a single plant. The flowers are white to cream in color and range from 10 millimeters (0.4 inch) to 30 millimeters (1.2 inches) in length.
The fruits produced are bright red and ovoid, often with one end thicker than the other and are edible and tastes like a cross between a strawberry and a kiwi.
A non-demanding species, mammillaria is a slow growing cactus. It requires moderate watering in summers and no water in the winter season. High level of sunlight is required for good flowering and spine maturation. It is susceptible to sunburn if moved quickly from shade to complete sunlight and hence needs time for adapting.
It is an excellent plant for garden rockery settings, desert type landscapes, patios and botanical gardens