Densely matted herb up to 3 cm. tall; stems and branches very delicate; internodes short, us. not > 5 mm. Lvs 1-2 mm. long, thin, linear- subulate to linear-oblong, subacute to acute, sts apiculate. Fls ± 1·5 mm. diam.; peduncles short; calyx lobes deep, ovate-oblong, obtuse. Petals white, ± twice length of sepals, oblong, obtuse. Scales 4, linear-cuneate. Carpels turgid; style oblique, very short, slightly recurved. Seeds (3)-4-(8).

n = 15 bivalents

2n = 30

2n = 56

Perennial herb forming small to large and extensive moss-like mats; stems almost prostrate except for slightly ascending tips, freely rooting at nodes, much-branched. Lvs connate at base, 0.5-2 × 0.2-0.5 mm, c. 0.2 mm thick, lanceolate-oblong, lanceolate-elliptic or oblanceolate, flattened above, strongly convex below; apex acute. Fls solitary in lf axils, star-like, 4-merous, 2.5-3.5 mm diam.; pedicels 0.5-3 mm long, elongating little at fruiting. Calyx lobes 0.4-0.6 × c. 4 mm, broadly ovate, obtuse or subacute. Petals 1-1.8 × 0.5-0.9 mm, broadly ovate or triangular-ovate, white, often flushed pink, obtuse, much > calyx. Scales c. 0.5 mm long, oblong-cuneate or oblanceolate. Follicles smooth. Seed 0.3-0.45 mm long.