N. conoidea is a cactus exemplar with a cone-like trunk, for this reason it is also commonly called "Cone cactus". Its stem is green or bluish-green and has well marked tubercles. The strong point of this cactus are its spines: from the white fluffy areolas emerge the radial spines arranged in rays, numerous, thin and white. The central units, instead, are more robust , longer and black in color, for a very eye-catching visual effect. During the flowering period, spring-summer, its beautiful funnel-shaped flowers bloom at the apex of the plant, with shades of pink or fuchsia.