Xyris flabelliformis, the savannah yelloweyed grass, is a North American species of flowering plant in the yellow-eyed-grass family. It is native to the coastal plain of the United States from eastern Mississippi to the Carolinas. Xyris flabelliformis is a perennial herb up to 30 cm (12 inches) tall with thread-like leaves up to 10 cm (4 inches) long, and yellow flowers.