Perennial of the Caryophyllaceae family, Arenaria grandiflora is widespread in southern Europe, from the Pyrenees to the Balkans, including the southern Alps, the Apennines, and the Iberian Peninsula. It colonizes rockeries, limestone slabs, open dry lawns, and rock crevices in full light, at altitudes between approximately 500 and 2,000 meters.
It reveals a dense and rounded cushion habit, with an intense bright green, formed of very tight stems adorned with small linear and acicular leaves, closely imbricated, giving the tuft an almost bristling texture, reminiscent from afar of certain cushion saxifrages. This compact and well-structured foliage is already a decorative element in its own right outside of flowering.
What immediately distinguishes this species among Arenaria is the size of its flowers: much larger than the average of the genus, they are pure white with five narrowly oval petals, distinctly spaced, revealing the yellowish-green calyx between them. Carried by fine branched peduncles, they unfold in a cloud above the cushion and cover it entirely at full bloom. In its natural habitat, flowering extends from May to July. In cultivation, it can start as early as April-May.
It thrives in full sun, in a limestone, poor and perfectly drained soil, hardy and undemanding once established.