Arenaria montana (Mountain sandwort) is a species of flowering plant in the family Caryophyllaceae, native to mountainous regions of southwestern Europe, from the Pyrenees to Portugal.
Arenaria montana is an evergreen perennial growing 14–22 cm (6–9 in) tall, with lanceolate or ovate green to grayish-green opposite leaves 0.5 to 1 inches (1 to 3cm) in length.
From mid to late Spring it produces dense clumps of white to near-white flowers approximately 2.5 cm (1 in) in diameter borne on cymes of 2 to 10 flowers each.
Arenaria montana prefers well drained, sandy to sandy loam soils, of moderate (pH 5.5 to 7.5) acidity. It also prefers moist soils, as its shallow root system leaves it vulnerable to drought.
This plant has gained the Royal Horticultural Society's Award of Garden Merit.