The monocotyledons (or, in abbreviated form, the monocots), class Liliopsida, are one of the major groups of flowering plants (angiosperms). There are about 100 families and 67,000 species of monocots, and the monocots consequently represent about one-fourth of the approximately 250,000 species of flowering plants. Some of the larger families of monocots are the grass family (Poaceae, or Gramineae), palm family (Arecaceae, or Palmae), and orchid family (Orchidaceae).

Economic and Ecologic Importance

Many of the most important plant species grown for human consumption are in the grass family, which includes rice, corn (maize), wheat, rye, barley, teff, millet, and other species. Many species of the grass family are also grown for animal consumption or as lawn grasses; examples include timothy, fescue, and bluegrass. Another group of great economic importance is the palm family, which includes coconuts, dates, and the oil palm. In addition to these foods, the palm family provides construction...