Arenaria serpyllifolia

Annual herb.

5–20 cm high.

The stem is erect or ascending, typically with multiple branches, and short-pubescent.

The leaves are opposite, nearly sessile, 2.5–6.5 mm long, deltate to ovate, acute, single-ribbed, grayish green and puberulent.

The flowers are numerous. The pedicels are 5–10 mm long. The sepals are 3–4.5 mm long and acute. The petals are 3–4 mm long, shorter than the calyx, not unguiculate, simple, entire and white. The gynoecium consists of three carpels.

The dehiscent capsule has six valves and is pyriform, thick-walled, light brown and as long as the calyx. The seeds (0.5 mm) do not bear elaiosomes.