Xyris, the yelloweyed grasses, is a genus of flowering plants in the Yellow-eyed-grass family. The genus counts over two hundred fifty species, widespread over much of the world, with the center of distribution in the Guianas.The leaves are mostly distichous, linear, flat and thin or round with a conspicuous sheath at the base. They are arranged in a basal aggregation. The small, yellow flowers are dioecious, borne on a spherical or cylindrical spike or head (inflorescence).