CYPERALES

order of flowering plants belonging to the class Liliopsida (monocotyledons). The Cyperales are generally annual or perennial herbs; a few are woody. They have reduced, mostly wind-pollinated or self-pollinated flowers. The flowers have a unilocular ovary with two to three carpels and a single ovule; the ovary ripens into an indehiscent fruit. The flowers form simple or complex spikes or spikelets that represent reduced inflorescences. The perianth is lacking or is represented by a set of bristles or tiny scales. The leaves generally have a well-defined sheath and a parallel-veined, usually narrow and elongated blade; often there is a small adaxial appendage, called a ligule, at the junction of the sheath and blade. The order contains two families: the Cyperaceae, or sedges, with about 5,000 species; and the Poaceae (q.v.; also called Gramineae), or grasses, with some 8,000 to 10,000 species. The Poaceae are one of the most important families of plants; grasses form the dominant vegetation over large portions of the Earth. Some authorities have classified the Cyperaceae and Poaceae as separate, unifamilial orders: Cyperales and Poales (or Graminales).