Its name derives from Greek and literally means "flower at the apex", referring to the main feature that distinguishes this genus from the similar Mammillaria, which is the presence of lively inflorescences which bloom exactly on the top of the stem. These are spherical cacti, of a small size and rather slow growth, which have alternating tubercles instead of the classic ribs. The spines are typically arranged in a radius on the areoles, giving to the plant, together with the tubercles, an extremely precise and perfectly geometric look. Its strong point, together with easy cultivation, is undoubtedly its showy and brightly colored flower, which is generally solitary, however your cactacea can give you an incredible view of more inflorescences blooming at the same time!