This annual produces masses of red, pink to pinkish white flowers up to 4cm long on tall thin stems. The spear-shaped leaves generally have a dark patch in the centre, but not always. The plant can grow up to 80 cm tall.
It flowers June to October, and it is found on wasteland, cultivated land, gardens, and damp habitats like riverbanks and floodplains. A native species, and common and widespread throughout.