Poaceae ( ) or Gramineae is a large and almost ubiquitous family of monocotyledonous flowering plants known as grass , commonly referred to collectively as grass . Poaceae includes cereal grass, bamboo and natural grassland meadows and grass and grasslands cultivated. The grass has a hollowed stem except at the node and a narrow alternative leaf is borne in two ranks. The bottom of each leaf encloses the stem, forming a leaf sheath. With about 780 genera and about 12,000 species, Poaceae is the fifth largest family of plants, following Asteraceae, Orchidaceae, Fabaceae, and Rubiaceae.
Grasslands such as savanna and grasslands where the dominant grass is estimated to be 40.5% of Earth's land area, including Greenland and Antarctica. Grass is also an important part of vegetation in many other habitats, including wetlands, forests and tundra. The Poaceae is the most economically important plant family, providing staple food from pet cereal plants such as corn, wheat, rice, barley, and millet and forage, building materials (bamboo, straw, straw) and fuel (ethanol).
Although they are commonly called "grass", seagrass, rush, and sediment fall outside this family. The turmoil and sediment associated with Poaceae, became members of the Poales order, but the seagrass was a member of the Order of Alismatales.
Video Poaceae
Etimologi
The name Poaceae was given by John Hendley Barnhart in 1895, based on the Poeae tribe described in 1814 by Robert Brown, and the genus of Poa species described in 1753 by Carl Linnaeus. This term comes from Ancient Greek ??? (pÃÆ'³a, "livestock feed").
Maps Poaceae
Evolutionary history
Grass includes some of the most versatile plant life forms. They become widespread towards the end of the Cretaceous period, and fossilized dinosaur impurities (coprolites) have been found to contain phytoliths of a variety that include grasses associated with modern rice and bamboo. The grass has adapted to conditions in dense rain forests, dry deserts, cold mountains and even intertidal habitats, and is currently the most widespread plant species; grass is a valuable source of food and energy for all types of wildlife and organic.
The cladogram shows subfamilies and the approximate number of species in brackets:
Prior to 2005, fossil findings show that grass evolved about 55 million years ago. The latest findings of the grass-like phytoliths in Kapurrol's chalked copolyte have propelled this date back to 66 million years ago. In 2011, the dating revision of the origin of the Oryzeae rice tribe suggested dates as early as 107 to 129 Mya. A multituberculate mammal with the adaptation of "grass eating" seems to indicate that the grass is about 120 mya.
Wu, you & amp; Li (in press) describes a microfossil of grass extracted from a specimen of the norrosi Equatorial Dinosaurs Equijubus from the Early-Beginning Monkey (Albian) Zhonggou Formation (China). The authors note that India became separated from Antarctica, and therefore also all other continents, roughly at the beginning of the end of Aptian, so the presence of grass in India and China during Cretaceous shows that the ancestors of Indian grass must have existed before it was too late. Aptian. Wu, you & amp; Li considers the Barremian origin for grass to be possible
The relationship between the three subfamilies Bambusoideae, Oryzoideae and Pooideae in the BOP clade has been completed: Bambusoideae and Pooideae are more closely related to each other than Oryzoideae. This separation occurs within a relatively short span of 4 million years.
According to Lester Charles King, the spread of grasses in Late Cenozoic will change the pattern of evolution of the hillslope that supports convex, sloping, concave, concave, and no face-free slopes are common. King argues that this is the result of a slower surface washing caused by a grass carpet which in turn will result in relatively more seepage of soil.
Description
Grasses may be annual or yearly crops, generally with the following characteristics (picture galleries can be used for reference): Grass stems, called rods, are usually cylindrical (more rarely flat, but not 3-angled) and hollow, plugged in knots, leaf attached. The grass leaves are almost always alternating and distichous (in one plane), and have parallel veins. Each leaf is divided into a bottom sheath that embraces the stems and blades with all the margins (ie smooth). The leaves of many grass blades are hardened with silica phytolith, which prevents grazing animals; some, like sword grass, are sharp enough to cut human skin. Complementary or peripheral hair called ligule lies at the intersection between the sheath and blade, preventing water or insects from entering into the sheath.
The Poaceae flowers are typically arranged in spikelets, each having one or more flower buds. Spikelets are further grouped into panicles or spikes. The part of the spikelet containing the florets is called rachilla. Spikelet consists of two (or sometimes fewer) bracts on the base, called a glume, followed by one or more buds. A floret consists of flowers surrounded by two bracts, one external - lemma - and one internal - palea. The flowers are usually hermaphroditic - maize is an important exception - and especially anemophilous or wind-pollinated, although sometimes insects play a role. The perianth is reduced to two scales, called lodicules , which expand and contract to spread lemma and palea; this is generally interpreted as modified sepals. This complex structure can be seen in the picture on the right, depicting the spikelet's wheat ( Triticum aestivum ). The fruit of the grass is caryopsis, where the skin of the seed melts into the fruit wall. Tillers are leaf shoots other than the first shoots produced from seeds.
Growth and development
A blade of grass grows at the base of the blade and not from the long end of the rod. This low growth point evolves in response to grazing animals and allows the grass to be grazed or cut regularly without severe damage to the plant.
Three general classifications of growth habits are present in grass: cluster-type (also called caespitose), stoloniferous, and rhizomatous. The success of grass partially lies in the process of morphology and their growth and partly in their physiological diversity. Most grasses are divided into two physiological groups, using photosynthetic pathways C3 and C4 for carbon fixation. C4 grass has a photosynthetic pathway, linked to the special leaf anatomy of Kranz, which allows to improve the efficiency of water use, making them better adapt to hot, dry environments and those who lack carbon dioxide.
C3 grass is referred to as "winter" grass, while C4 plants are considered "warm seasons" of grass.
- The annual winter - wheat, rye, annual bluegrass (annual pasture, Poa annua ), and oats
- Perennial winter - orchardgrass (cocksfoot, Dactylis glomerata), fescue ( Festuca spp.), Kentucky bluegrass and perennial ryegrass ( Lolium perenne )
- Annual warm season - corn, sudangrass, and millet pearl
- Perpetual warmth season - big bluestem, Indiangrass, Bermudagrass, and switchgrass.
Distribution
The grass family is one of the most distributed and abundant plant groups on Earth. Grasses are found on every continent, including Antarctica with the presence of Antarctic hair grass on the Antarctic Peninsula.
Ecology
Grass is the dominant vegetation in many habitats, including grasslands, salt marshes, reedswamps and steppes. They also occur as a smaller part of the vegetation in almost every other terrestrial habitat. Biomes dominated by grass are called grasslands. If only a large and contiguous area of ​​grass is calculated, this biome covers 31% of the planet's land. Grasslands include pampas, steppes, and grasslands. The grass provides food for many grazing mammals - such as cattle, deer, and elephants - as well as many species of butterflies and moths. Many types of animals feed on grass as their main food source, and are called graminivores - these include cattle, sheep, horses, rabbits and many invertebrates, such as grasshoppers and caterpillars from many brown butterflies. Grass is also eaten by omnivores or even occasionally by carnivorous animals.
The grass is unusual because the meristem is located near the bottom of the plant; therefore, they can quickly recover from pruning at the top. The evolution of large grazing animals in Cenozoic contributed to the spread of grass. Without a large grazer, a flame-free area is rapidly colonized by grass, and with enough rain, tree seedlings. Trees eventually defeated most of the grass. Trampling grazers kill tree seedlings but not grass.
Taxonomy
There are about 12,000 grass species around 771 genera that are classified into 12 subfamilies. See full list of Poaceae genera.
- Anomochlooideae Pilg. ex Potztal, a small line of grassy grass covering two genera ( Anomochloa , Streptochaeta )
- Pharoideae L.G.Clark & ​​â € <â €
- Puelioideae L.G.Clark, M.Kobay., S.Mathews, Spangler & amp; E.A.Kellogg, a small lineage of African genus Puelia Pooideae, including wheat, barley, oats, brome-grass (Bromus ), bamboo-cured ( Calamagrostis ) and many grasses and pastures <
- Bambusoideae, including bamboo
- Ehrhartoideae, including rice and rice
- Aristidoideae, including Aristida
- Arundinoideae, including giant bamboo and general bamboo Chloridoideae, including lovegrass ( Eragrostis , about 350 species, including teff), droplets ( Sporobolus , about 160 species), finger millet ( Eleusine coracana (L.) Gaertn.), and muhly grass ( Muhlenbergia , about 175 species)
- Panicoideae, including panic grass, corn, sorghum, sugarcane, most millet, fonio, and bluestem grass
- Micrairoideae
- Danthonioideae, including pampas grass
Using
Grass, in human terms, is probably the most economical plant family. Their economic interests come from several regions, including food, industrial, and grass production. They have been grown as food for pets up to 6,000 years and grain grains such as wheat, rice, corn (corn) and barley have become the most important human food crops. Grass is also used in making straw, paper, fuel, clothing, insulation, wood for fencing, furniture, scaffolding and building materials, floor mats, sport grass and baskets.
Food production
Agricultural grass grown for edible beans is called cereal or grains (though the latter term, agriculturally, refers to cereals and beans). Of all the crops grown, 70% are grass. Three cereals - rice, wheat, and corn (corn) - provide more than half of all the calories consumed by humans. Cereals are a major source of carbohydrates for humans and may be the main sources of protein, including rice (in south and east Asia), maize (in Central and South America), and wheat and barley (in Europe, North Asia and America).
Sugarcane is the main source of sugar production. Food additives using sugar cane include seeds, buds, and rhizomes that grow, and in their drinks include cane juice and plant milk, as well as rum, beer, whiskey, and vodka.
Lemongrass is a grass that is used as a culinary herb for its citrus scent and aroma.
Many species of grass grow as grasslands for feeding or as forage for specified animal feed, especially in the case of cattle, horses, and sheep. Such grasses can be cut and stored for later feeding, especially for winter, in the form of bales of hay or straw, or in silos as silage. Straw (and sometimes straw) can also be used as a bedding for animals.
Industry
Grasses are used as raw materials for a variety of purposes, including construction and building material compositions such as cobs, for insulation, in paper making and boards such as oriented Structured Straw Board. Grass fiber can be used for making paper, and for biofuel production. Bamboo scaffolds are able to withstand hurricanes that will damage the steel scaffolding. Bigger bamboo and Arundo donax has a strong rod that can be used in a way similar to wood, Arundo is used to make reeds for woodwind instruments, and bamboo is used for tools that innumerable.
Phragmites australis (common bamboo) is important for hay and grass roots stabilize the soil from the tree house. Reeds are used in water treatment systems, wetland conservation and land reclamation in Afro-Eurasia. Marram Grass ( Ammophila arenaria ) Grass and decorative use
Grasses are the main crops used in grasslands, which come from pastures that are herded in Europe. They also provide important means of erosion control (eg along the roadside), especially on sloping ground. Grass lawn is an important cover of the playing surface in many sports, including soccer (soccer), American soccer, tennis, golf, cricket, softball and baseball.
Decorative grasses, such as annual cluster grasses, are used in many styles of garden design for foliage, inflorescences, seed heads. They are often used in natural landscapes, xeriscaping and slope stabilization in contemporary landscapes, wildlife gardening, and native gardening.
Sports grass
The grass playing field, course and field are the traditional playing surfaces for many sports, including American soccer, soccer associations, baseball, cricket, golf, and rugby. The surface of the grass is also sometimes used for horse racing and tennis. The type of maintenance and type of grass used may be an important factor for some sports, less important for others. In some sports facilities, including indoor domes and other places where pasture maintenance will be difficult, the grass can be replaced with synthetic grass, a substitute for synthetic turf.
Cricket
In cricket, the throw is a carefully trimmed and carefully rolled lawn where the bowler bowl is. In the days leading up to the match it was repeatedly trimmed and overthrown to produce a very flat surface so that the ball bounced.
Golf
The grass on the golf course is kept in three different conditions: the rough , fairway , and putting green . The grass on the fairway is short-trimmed and even, allowing players to hit the ball cleanly. Playing from the rough is a disadvantage because the long grass can affect the ball breakout. The grass on the putting green is the shortest and most evenly, ideally allowing the ball to roll smoothly over the surface. The entire industry revolves around the development and marketing of grass varieties for golf courses.
Tennis
In tennis, grasses grow on very dense ground, and the reflections of tennis balls can vary depending on the health of the grass, how it has recently been trimmed, and the wear of recent play. The surface is softer than hard courts and clay (other tennis surfaces), so the ball bounces lower, and the player must reach the ball faster resulting in different styles of play that may fit some more players than others. Among the world's most prestigious field for grass tennis is Center Court at Wimbledon, London which hosts the annual Wimbledon Championship final in England, one of the four Grand Slam tournaments.
Economically important grass
Role in society
Grass has long been important in human society. They have been cultivated as a feed for humans and pets for thousands of years. The main ingredient of beer is usually barley or wheat, both of which have been used for this purpose for over 4,000 years.
In some places, especially in the suburbs, lawn maintenance is a sign of homeowner responsibility to the overall appearance of their environment. One grass maintenance law work for:
... a desire for upward mobility and manifestation on the page. As Virginia Jenkins, author of The Lawn, says very bluntly, 'The upper middle class of America imitates the aristocratic community with their own small and semi-rural plantations.' In general, the lawn is one of the main selling points of these new suburban homes, because it shifts the social class designation of the equity and everywhere from urban homes connected to the streets by appointment of the upper middle class from space "healthy" green. and a status symbol that is the front page.
Many US municipalities and homeowners' associations have rules that require grass to be maintained to certain specifications, sanctioning those who let grass grow too long. In communities with drought problems, grass watering may be limited to a specific time of day or day of the week.
The smell of freshly cut grass is produced mainly by cis-3-Hexenal.
Some common pearl words involve grass. As an example:
- "The grass is always greener on the other side" indicating an alternate state will always look better than hers.
- "Do not let grass grow under your feet" tell someone to move.
- "A snake in the grass" means hidden dangers.
- "When elephants fight, the grass that suffers" tells the observers who are caught in the crossfire.
The people's myth of grass is that it refuses to grow in the place of a cruel death.
In popular culture
In John Christopher's
Picture gallery
See also
- Agrostology
- Grass rolls
- Forbs
- Decorative Grass
- Tempting
- Hurry
- PACMAD clade
References
External links
- The definition of a grass dictionary in Wiktionary
- Need a Definition of Grass?
- Vegetative Key for Grass
- Poaceae in Factory List
- Gramineae in Flower Plants Family (DELTA)
- Poaceae on Site Angiosperm Phylogeny
- Poaceae Classification from online New World Grass Catalog
- Poaceae online Guide to Mongolian Flora
- Poaceae online Flora of Taiwan
- Poaceae on the internet Flora of Pakistan
- Poaceae on the internet Flora Zimbabwe
- Poaceae online Flora of Western Australia
- Australian Grass (AusGrass2) - http://ausgrass2.myspecies.info/
- Gramineae on the internet New Zealand Flora
- NZ Grass Key Interactive Key for New Zealand Grass at Landcare Research
- Grass Genera of the World on DELTA intkey
- GrassBase - World Grass Flores at Royal Botanic Gardens - Kew
- GrassWorld - http://grassworld.myspecies.info/
Source of the article : Wikipedia
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