Annual Knawel arrives on the scene in winter, germinating during warm spells and spreading its wiry, tangled stems outward across disturbed ground, fields, and neglected lawns. The plants grow only 2 to 5 inches tall but can form surprisingly dense mats before the season turns. A member of the pink family (Caryophyllaceae), it produces tiny greenish flowers in early spring that pass almost unnoticed before the whole plant dies back by late spring or early summer.

Native to Eurasia and Africa, it has naturalized across much of North America since introduction. It thrives in sandy and gravelly soils where competition is low, tolerating drought and moderate moisture alike. In managed turf it is mostly a cosmetic nuisance rather than a serious threat, and it disappears on its own well before midsummer, leaving behind seeds that will germinate the following winter.