A perennial with square stems and whorls of 6 to 8 leaves. Smooth bedstraw is primarily a weed of landscapes, nursery crops, turfgrass, and lawns that is found throughout the United States. Cotyledons oval and occur on petioles that are notched at the apex. Occur in whorls of 6 to 8. Leaves are without hairs but may occasionally have hairs along the margins.
Stems are square in cross-section and without hairs.
Rhizomes and stolons occur. Flowers consist of 4 white petals. However, catchweed bedstraw has hairs on the upper leaf surfaces and also has stems with tiny prickles. Additionally, catchweed bedstraw does not have rhizomes or stolons like smooth bedstraw.