Perennial of the Caryophyllaceae family, Arenaria acerosa is an endemic species of Turkey, described by Boissier in 1849. It occupies rock gardens, screes, and rock crevices of the mountain ranges of Asia Minor, in full sun exposure, on well-drained to dry substrates.
At rest, it forms a dense and compact cushion, remarkably architectural, consisting of short woody stems adorned with very fine, bright green, needle-like leaves arranged in a star shape and tightly packed together — a structure that evokes more of a spiny cushion plant than a classic Caryophyllaceae. This firm and well-defined hemispherical habit is one of the most immediately striking features of the species outside of flowering.
During flowering, long, loose, and branched stems rise above the cushion, reaching 10 to 20 cm, bearing a multitude of small flowers with five widely spaced white petals, with a slightly greenish center, gathered in airy cymes of great lightness. The contrast between the rigor of the cushion and the freedom of the inflorescence is striking. In its natural habitat, flowering probably extends from May to July depending on the altitude.
The plant requires a mineral, very well-drained, poor soil, in full light; it does not tolerate stagnant moisture, especially in winter. It is perfectly suited for cultivation in rock gardens, wall crevices, or alpine troughs.