Generalities: globular or slightly columnar cactus from Mexico. The number of species belonging to this genus is controversial, due to the variability of the forms and the similarity of some species to other cactaceae, usually the number is around ten. In nautra the stenocactus live in rocky deserts or in the plains, they have numerous thin and waxy ribs, often even more than eighty, very particular in that they are wavy. The areolas are usually small and carry many thorns, straight or curved, never hooked; the central spine is usually very long, up to 6-8 cm. In the spring they produce in the highest part some small funnel flowers, white, pink or red, whose petals have a darker line that divides them in half.
Exposure: these cactaceae love very bright positions, even in full sun; they fear the cold and do not bear temperatures below 5-6 degrees, for this reason it is advisable to hospitalize them at home during the winter or in a sheltered place.
Watering: during the growing season, water at least once a week, waiting for the soil to be dry between one watering and another; in winter, water more rarely, once a month or less if the plant is kept indoors, if instead the stenocactus is placed in a colder place, it is advisable to suspend the watering completely to allow the winter rest of the plant. From March to October add a fertilizer for succulents to the irrigating water every 15-20 days.