Arenaria serpyllifolia is a small annual herb, to 20 cm, diffusely branched, wiry, stems slightly hairy, internodes usually longer than leaves.
Leaves opposite, egg-shaped, margin hairy, rough textured, to 0.5 cm long, 0.4 cm long, similar to common chickweed but leaves smaller.
Flowers white, petals 5, entire, usually shorter than sepals; blooms May-Aug.
Fruit dry, hollow, an ovoid, 6-valved capsule, seeds numerous.
Wetland status: FAC.
Frequency in NYC: Infrequent.
Habitat: Open areas, roadsides, sandy soil.