The name of this genus, which includes very few species, derives from Oroya, the capital of the province of Yauli, in Peru, which is the place of origin, where, in the high Andean mountains, this cactus was found. It is undoubtedly one of the most cold-tolerant South American species, consisting of a globular or slightly cylindrical stem of a limited size, with well-defined vertical ribs, on which various spines sprout, generally the stem is of a typical yellowish color. It is highly appreciated for its resistance, in spring and summer it will liven up your gardens with lovely bell-shaped flowers in bright shades, that bloom at the top of the plant and create a pleasant contrast with the bright green color of the plant! Here are some tips for its cultivation: It likes an exposure to full sun in rather airy locations. It is preferable to keep it at mild temperatures and never below 8 °C, for this reason it is recommended to shelter it during the winter period. Water moderately, only when the soil is completely dry. It is enough to water the plant once a week in spring and summer, once a month in autumn and to suspend watering completely in winter. The best soil is a well-draining one, even better if further enriched with inert materials such as pumice or lapilli. They do not need frequent fertilization, it is sufficient to dilute the fertilizer with watering once a year.