The grass family, known formerly as Gramineae; a very large and important family of monocotyledons, most of which are annual or perennial herbs, but a few genera of which (e.g. the bamboos) are woody. From an ecological viewpoint, it is the most successful family of flowering plants. Where forests have been destroyed, grasses have tended to replace the trees as the dominant vegetation. The Poaceae includes the cereal grasses, including wheat, barley, oats, maize, rice, and millet, making it the most economically important of all plant families. Many grasses are important sources of fibres. Most grasses have hollow stems with solid nodes containing intercalary meristem and leaves in two opposite and alternating rows. Each leaf consists of a sheath around the culm, a blade, and usually a flap or ligule at the junction of sheath and blade. Inflorescences are very varied, but are usually composed of spikelets, each with a pair of sterile glumes at the base. Each spikelet consists of 1 to many florets, each floret normally having 2 subtending scales (the lower chaffy lemma and the upper membranaceous palea), 3 stamens with long filaments and flexible anthers (adapted to wind pollination), and an ovary with 1 ovule and 2 long, feathery stigmas. There are 660 genera with about 10,000 species, distributed throughout the world.
Subjects: Plant Sciences and Forestry.