Mammillaria marksiana

It is a geometrically accurate spherical cactus, concave at the apex, generally solitary. This bright light green cactus has large protruding tubercles of a conical shape, from which golden short spines come out, arranged in a star shape. Between the grooves, a short white down separates the tubercles. Its lime yellow flowers are small, when bloom, they form a corolla around the apex.