7cm diameter. Eriosyce senilis is endemic to various locality of Coquimbo (Region 04) - Chile. It is a solitary cactus with dens covering of bristly spines, it hybridize easily in habitat and in cultivation too with other species of the genus Eriosyce. The ssp. senilis has thin cream-white twisted spines but is quite variable in spination and the plants with different spine colours are often found in cultivation labelled as Eriosyce senilis var. multicolor.