Its name was chosen in honor of the botanist Mauel Fraile, who first discovered it. These small plants are of a round shape, do not exceed 3 centimeters in diameter, but the seedlings usually tend to grow next to each other, forming small clusters. It is of dark green or brownish colors, which allow it to blend in with the rocks, among which it grows spontaneously in its natural habitat. Its small but very decorative yellow or brown spines stand out along the short stems. These graceful cacti have a very particular floral characteristic: its large yellow inflorescences are able to pollinate, even if the flower usually opens up just for an hour, while it remains closed for the rest of the time. Here we talk about a very particular cleistogamous plant!