Yellow-Eyed Grass, the common name for plants of the genus xyris (Gr. vpis, some plant with two-edged leaves), which consists of biennial or perennial rush-like plants, and gives its name to a small order of endogens, the xyridacece. The plants have sword-shaped leaves sheathing the base of an otherwise naked stem, which in the different species is from 2 in. to 4 ft. high, cylindrical or flattened, and bearing at its summit an ovoid or oblong spike, consisting of rounded, firm, sometimes crustaceous, imbricated bracts, from the axil of each of which a small yellow flower is produced. The calyx consists of three sepals, the two lateral boat-shaped, and often fringed on the keel; the petals three; stamens six, the three alternate ones sterile and often bearded at the summit; the one-celled, three-valved capsule containing numerous small seeds. More than 50 species are described, of which about 15 belong to the United States, especially southward; one species, X. flexwm, and its variety pusiila, extend from Vermont to Lake Superior; they mostly grow in sandy swamps and pine barrens, where they produce their small, bright yellow flowers all summer.

Though of no economical importance, the plants are of much interest to the botanist.