The variegated shape of this cactus has yellow spots or streaks in the exact points of the epidermis where there is a lack of chlorophyll; these stains will never be identical in different plants thus making each of them unique in its kind and for this reason much appreciated by collectors around the world. N. chilensis in the normal form is a spherical cactus that with growth tends to become cylindrical. Its stem with an intense green colour is equipped with marked longitudinal ribs It has oval areoles from which thick long and well straight spines sprout, in which it is not difficult to distinguish some robust spines, surrounded by many other very thin spines. It is characterized by funnel-shaped inflorescences at the apex of the plant, formed by thin petals and arranged in several layers, sometimes each of a different shade but generally tending to white.