It is a cactus with very slow growth but that, with time, will tend to reach considerable size. H . fernowii is a cactus with a particular appearance, whose green stem has well marked and visible tubercles. From the white and woolly areoles, positioned at the apex of the tubercles, thin radial thorns of yellowish colour come out, whilst the central ones tend to be more robust and darker. During the flowering period this wonderful cactus gives us flowers daisies with white petals, which give it a delicacy and elegance truly unique!