poaceae () or gramineae ()  is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses.it includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns and pasture.the latter are commonly referred to collectively as grass.with around 780 genera and around 12,000 species, the poaceae is the fifth-largest plant family, following the asteraceae, orchidaceae, fabaceae and rubiaceae.the poaceae are the most economically important plant family, providing staple foods from domesticated cereal crops such as maize, wheat, rice, barley, and millet as well as feed for meat-producing animals.they provide, through direct human consumption, just over one-half (51%) of all dietary energy; rice provides 20%, wheat supplies 20%, maize (corn) 5.5%, and other grains 6%.some members of the poaceae are used as building materials (bamboo, thatch, and straw); others can provide a source of biofuel, primarily via the conversion of maize to ethanol.grasses have stems that are hollow except at the nodes and narrow alternate leaves borne in two ranks.the lower part of each leaf encloses the stem, forming a leaf-sheath.the leaf grows from the base of the blade, an adaptation allowing it to cope with frequent grazing.grasslands such as savannah and prairie where grasses are dominant are estimated to constitute 40.5% of the land area of the earth, excluding greenland and antarctica.grasses are also an important part of the vegetation in many other habitats, including wetlands, forests and tundra.though they are commonly called 'grasses', groups such as the seagrasses, rushes and sedges fall outside this family.the rushes and sedges are related to the poaceae, being members of the order poales, but the seagrasses are members of order alismatales.however, all of them belong to the monocot group of plants.grass leaves are nearly always alternate and distichous (in one plane), and have parallel veins.: 11  each leaf is differentiated into a lower sheath hugging the stem and a blade with entire (i.e., smooth) margins.: 11  the leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals; some, such as sword grass, are sharp enough to cut human skin.a membranous appendage or fringe of hairs called the ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath.: 11   flowers of poaceae are characteristically arranged in spikelets, each having one or more florets.: 12  the spikelets are further grouped into panicles or spikes.the part of the spikelet that bears the florets is called the rachilla.a spikelet consists of two (or sometimes fewer) bracts at the base, called glumes, followed by one or more florets.: 13  a floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea.the flowers are usually hermaphroditic—maize being an important exception—and mainly anemophilous or wind-pollinated, although insects occasionally play a role.the perianth is reduced to two scales, called lodicules,: 11  that expand and contract to spread the lemma and palea; these are generally interpreted to be modified sepals.the fruit of grasses is a caryopsis, in which the seed coat is fused to the fruit wall.: 16  a tiller is a leafy shoot other than the first shoot produced from the seed.: 11    === growth and development ===  grass blades grow at the base of the blade and not from elongated stem tips.this low growth point evolved in response to grazing animals and allows grasses to be grazed or mown regularly without severe damage to the plant.: 113–114 three general classifications of growth habit present in grasses: bunch-type (also called caespitose), stoloniferous, and rhizomatous.
poaceae | division | flowering plant <tsp> ardmore airport new zealand | 2nd runway surfacetype | poaceae <tsp> poaceae | order | poales
poaceae () or gramineae ()  is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses.with around 780 genera and around 12,000 species, the poaceae is the fifth-largest plant family, following the asteraceae, orchidaceae, fabaceae and rubiaceae.the poaceae are the most economically important plant family, providing staple foods from domesticated cereal crops such as maize, wheat, rice, barley, and millet as well as feed for meat-producing animals.the rushes and sedges are related to the poaceae, being members of the order poales, but the seagrasses are members of order alismatales.