Tufted perennial with linear leaves, having the appearance of a clump of grass, basal leaves up to 6 cm in length. Stems leaves are few, treadlike, opposite. Flowers are small, white in colour, 5 petals, flowers to 10 mm diameter, in cymes. Plants glabrous. Plants begin to flower in late May.
Height listed in Budd's Flora to 30 cm, the plants observed were to 15 cm in height.
Part of the key to identifying Arenaria species in Budd's Flora is the shape of the tip of the sepals, whether they are "rounded or obtuse" versus "acute to acuminate". I found both types of sepals. The Taxanomic Reminder for Recognizing Saskatchewan Plants lists as identifiers for the species 1) leaves 2-6 cm, and 2) cyme dense.
Habitat is dry plains and slopes in Wood Mountain and the Cypress uplands.
Not common, listed as an S3 by the Saskatchewan Conservation Data Centre.
Photos taken June 2nd, dry grassland, Old Man on His Back Conservation Area, about 500 km southwest of our home in Regina, SK