A monocot plant (family Poaceae) that is an annual or perennial herb with a few woody species, which produces rhizomes or stolons, or grows in dense tufts. It has fibrous roots that in many species are augmented by adventitious roots growing from the stem, so each stem has its own root system, allowing the plant to grow to a large size and great age. In most species the leaves are long and narrow, and enclosed in a sheath. Flowers are spikelets. Grasses are the most successful of plants, the family comprising 707 genera with 11,337 species, found worldwide, and including cereal crops, pasture grasses, bamboos, sugar cane, and many more.