Xyris serotina, the acidswamp yelloweyed grass, is a North American species of flowering plants in the yellow-eyed-grass family. It grows on the coastal plain of the southeastern United States from eastern Louisiana to the Carolinas. Xyris serotina is a perennial herb with a stem up to 60 cm (2 feet) tall with long, narrow leaves up to 20 cm (8 inches) long.