Poaceae or Gramineae is a large and nearly ubiquitous family of monocotyledonous flowering plants known as grasses referred to collectively as grass. Poaceae includes the cereal grasses and the grasses of natural grassland and cultivated lawns and pasture. 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. With around 780 genera and around 12,000 species, Poaceae are the fifth-largest plant family, following the Asteraceae, Orchidaceae and Rubiaceae. 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 an important part of the vegetation in many other habitats, including wetlands and tundra; the Poaceae are the most economically important plant family, providing staple foods from domesticated cereal crops such as maize, rice and millet as well as forage, building materials and fuel.
Though they are called "grasses", seagrasses 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; the name Poaceae was given by John Hendley Barnhart in 1895, based on the tribe Poeae described in 1814 by Robert Brown, the type genus Poa described in 1753 by Carl Linnaeus. The term is derived from the Ancient Greek πόα. Grasses include some of the most versatile plant life-forms, they became widespread toward the end of the Cretaceous period, fossilized dinosaur dung have been found containing phytoliths of a variety that include grasses that are related to modern rice and bamboo. Grasses have adapted to conditions in lush rain forests, dry deserts, cold mountains and intertidal habitats, are the most widespread plant type. A cladogram shows subfamilies and approximate species numbers in brackets: Before 2005, fossil findings indicated that grasses evolved around 55 million years ago.
Recent findings of grass-like phytoliths in Cretaceous dinosaur coprolites have pushed this date back to 66 million years ago. In 2011, revised dating of the origins of the rice tribe Oryzeae suggested a date as early as 107 to 129 Mya. Wu, You & Li described grass microfossils extracted from a specimen of the hadrosauroid dinosaur Equijubus normani from the Early Cretaceous Zhonggou Formation; the authors noted that India became separated from Antarctica, therefore all other continents at the beginning of late Aptian, so the presence of grasses in both India and China during the Cretaceous indicates that the ancestor of Indian grasses must have existed before late Aptian. Wu, You & Li considered the Barremian origin for grasses to be probableThe relationships among the three subfamilies Bambusoideae and Pooideae in the BOP clade have been resolved: Bambusoideae and Pooideae are more related to each other than to Oryzoideae; this separation occurred within the short time span of about 4 million years.
According to Lester Charles King the spread of grasses in the Late Cenozoic would have changed patterns of hillslope evolution favouring slopes that are convex upslope and concave downslope and lacking a free face were common. King argued that this was the result of more acting surface wash caused by carpets of grass which in turn would have resulted in more soil creep. Grasses may be annual or perennial herbs with the following characteristics: The stems of grasses, called culms, are cylindrical and are hollow, plugged at the nodes, where the leaves are attached. Grass leaves are nearly always alternate and distichous, have parallel veins; each leaf is differentiated into a lower sheath hugging a blade with entire margins. The leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals. 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. Flowers of Poaceae are characteristically arranged in each having one or more florets.
The spikelets are further grouped into spikes. The part of the spikelet that bears the florets is called the rachilla. A spikelet consists of two bracts at called glumes, followed by one or more florets. A floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea; the flowers are hermaphroditic—maize being an important exception—and anemophilous or wind-pollinated, although insects play a role. The perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea; this complex structure can be seen in the image on the right. The fruit of grasses is a caryopsis. A tiller is a leafy shoot other than the first shoot produced from the seed. 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 without severe damage to the plant. Three general classifications of growth habit present in g
Sandstone is a clastic sedimentary rock composed of sand-sized mineral particles or rock fragments. Most sandstone is composed of quartz or feldspar because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in Bowen's reaction series. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, yellow, grey, pink and black. Since sandstone beds form visible cliffs and other topographic features, certain colors of sandstone have been identified with certain regions. Rock formations that are composed of sandstone allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity. Quartz-bearing sandstone can be changed into quartzite through metamorphism related to tectonic compression within orogenic belts.
Sandstones are clastic in origin. They are formed from cemented grains that may either be fragments of a pre-existing rock or be mono-minerallic crystals; the cements binding these grains together are calcite and silica. Grain sizes in sands are defined within the range of 0.0625 mm to 2 mm. Clays and sediments with smaller grain sizes not visible with the naked eye, including siltstones and shales, are called argillaceous sediments; the formation of sandstone involves two principal stages. First, a layer or layers of sand accumulates as the result of sedimentation, either from water or from air. Sedimentation occurs by the sand settling out from suspension. Once it has accumulated, the sand becomes sandstone when it is compacted by the pressure of overlying deposits and cemented by the precipitation of minerals within the pore spaces between sand grains; the most common cementing materials are silica and calcium carbonate, which are derived either from dissolution or from alteration of the sand after it was buried.
Colors will be tan or yellow. A predominant additional colourant in the southwestern United States is iron oxide, which imparts reddish tints ranging from pink to dark red, with additional manganese imparting a purplish hue. Red sandstones are seen in the Southwest and West of Britain, as well as central Europe and Mongolia; the regularity of the latter favours use as a source for masonry, either as a primary building material or as a facing stone, over other forms of construction. The environment where it is deposited is crucial in determining the characteristics of the resulting sandstone, which, in finer detail, include its grain size and composition and, in more general detail, include the rock geometry and sedimentary structures. Principal environments of deposition may be split between terrestrial and marine, as illustrated by the following broad groupings: Terrestrial environmentsRivers Alluvial fans Glacial outwash Lakes Deserts Marine environmentsDeltas Beach and shoreface sands Tidal flats Offshore bars and sand waves Storm deposits Turbidites Framework grains are sand-sized detrital fragments that make up the bulk of a sandstone.
These grains can be classified into several different categories based on their mineral composition: Quartz framework grains are the dominant minerals in most clastic sedimentary rocks. These physical properties allow the quartz grains to survive multiple recycling events, while allowing the grains to display some degree of rounding. Quartz grains evolve from plutonic rock, which are felsic in origin and from older sandstones that have been recycled. Feldspathic framework grains are the second most abundant mineral in sandstones. Feldspar can be divided into two smaller subdivisions: plagioclase feldspars; the different types of feldspar can be distinguished under a petrographic microscope. Below is a description of the different types of feldspar. Alkali feldspar is a group of minerals in which the chemical composition of the mineral can range from KAlSi3O8 to NaAlSi3O8, this represents a complete solid solution. Plagioclase feldspar is a complex group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8.
Lithic framework grains are pieces of ancient source rock that have yet to weather away to individual mineral grains, called lithic fragments or clasts. Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock, although the most common lithic fragments found in sedimentary rocks are clasts of volcanic rocks. Accessory minerals are all other mineral grains in a sandstone. Common accessory minerals include micas, olivine and corundum. Many of these accessory grains are more dense than the silicates that
The coast known as the coastline or seashore, is the area where land meets the sea or ocean, or a line that forms the boundary between the land and the ocean or a lake. A precise line that can be called a coastline cannot be determined due to the Coastline paradox; the term coastal zone is a region where interaction of the land processes occurs. Both the terms coast and coastal are used to describe a geographic location or region. Edinburgh for example is a city on the coast of Great Britain. A pelagic coast refers to a coast which fronts the open ocean, as opposed to a more sheltered coast in a gulf or bay. A shore, on the other hand, can refer to parts of land adjoining any large body of water, including oceans and lakes; the somewhat related term "" refers to the land alongside or sloping down to a river or body of water smaller than a lake. "Bank" is used in some parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond. While many scientific experts might agree on a common definition of the term "coast", the delineation of the extents of a coast differ according to jurisdiction, with many scientific and government authorities in various countries differing for economic and social policy reasons.
According to the UN atlas, 44% of people live within 150 kilometres of the sea. Tides determine the range over which sediment is deposited or eroded. Areas with high tidal ranges allow waves to reach farther up the shore, areas with lower tidal ranges produce deposition at a smaller elevation interval; the tidal range is influenced by the shape of the coastline. Tides do not cause erosion by themselves. Waves erode coastline. Coastlines with longer shores have more room for the waves to disperse their energy, while coasts with cliffs and short shore faces give little room for the wave energy to be dispersed. In these areas the wave energy breaking against the cliffs is higher, air and water are compressed into cracks in the rock, forcing the rock apart, breaking it down. Sediment deposited by waves comes from eroded cliff faces and is moved along the coastline by the waves; this forms an cliffed coast. Sediment deposited by rivers is the dominant influence on the amount of sediment located on a coastline.
Today riverine deposition at the coast is blocked by dams and other human regulatory devices, which remove the sediment from the stream by causing it to be deposited inland. Like the ocean which shapes them, coasts are a dynamic environment with constant change; the Earth's natural processes sea level rises and various weather phenomena, have resulted in the erosion and reshaping of coasts as well as flooding and creation of continental shelves and drowned river valleys. The coast and its adjacent areas on and off shore are an important part of a local ecosystem: the mixture of fresh water and salt water in estuaries provides many nutrients for marine life. Salt marshes and beaches support a diversity of plants and insects crucial to the food chain; the high level of biodiversity creates a high level of biological activity, which has attracted human activity for thousands of years. More and more of the world's people live in coastal regions. Many major cities have port facilities; some landlocked places have achieved port status by building canals.
The coast is a frontier that nations have defended against military invaders and illegal migrants. Fixed coastal defenses have long been erected in many nations and coastal countries have a navy and some form of coast guard. Coasts those with beaches and warm water, attract tourists. In many island nations such as those of the Mediterranean, South Pacific and Caribbean, tourism is central to the economy. Coasts offer recreational activities such as swimming, surfing and sunbathing. Growth management can be a challenge for coastal local authorities who struggle to provide the infrastructure required by new residents. Coasts face many human-induced environmental impacts; the human influence on climate change is thought to contribute to an accelerated trend in sea level rise which threatens coastal habitats. Pollution can occur from a number of sources: industrial debris. Fishing has declined due to habitat degradation, trawling and climate change. Since the growth of global fishing enterprises after the 1950s, intensive fishing has spread from a few concentrated areas to encompass nearly all fisheries.
The scraping of the ocean floor in bottom dragging is devastating to coral and other long-lived species that do not recover quickly. This destruction alters the functioning of the ecosystem and can permanently alter species composition and biodiversity. Bycatch, the capture of unintended species in the course of fishing, is returned to the ocean only to die from injuries or exposure. Bycatch represents about a quarter of all marine catch. In the case of shrimp capture, the bycatch is five times larger, it is believed that melting Arctic ice will cause sea levels to rise and flood coas
Lupinus known as lupin or lupine, is a genus of flowering plants in the legume family, Fabaceae. The genus includes with centers of diversity in North and South America. Smaller centers occur in the Mediterranean, they are cultivated, both as a food source and as ornamental plants. The species are herbaceous perennial plants 0.3–1.5 m tall, but some are annual plants and a few are shrubs up to 3 m tall. An exception is the chamis de monte of Oaxaca in Mexico, a tree up to 8 m tall. Lupins have soft green to grey-green leaves which may be coated in silvery hairs densely so; the leaf blades are palmately divided into five to 28 leaflets, or reduced to a single leaflet in a few species of the southeastern United States. The flowers are produced in each flower 1 -- 2 cm long; the pea-like flowers have an upper standard, or banner, two lateral wings, two lower petals fused into a keel. The flower shape has inspired common names such as bluebonnets and quaker bonnets; the fruit is a pod containing several seeds.
The legume seeds of lupins called lupin beans, were popular with the Romans, who cultivated the plants throughout the Roman Empire. Seeds of various species of lupins have been used as a food for over 3000 years around the Mediterranean and for as long as 6000 years in the Andes. Lupins were used by many Native American peoples such as the Yavapai in North America; the Andean lupin or tarwi was a widespread food in the Incan Empire. The pearl lupin of the Andean highlands of South America, Lupinus mutabilis, known locally as tarwi or chocho, was extensively cultivated, but no conscious genetic improvement other than to select for larger and water-permeable seeds seems to have been made. Users soaked the seed in running water to remove most of the bitter alkaloids and cooked or toasted the seeds to make them edible, or else boiled and dried them to make kirku, reported as a pre-Columbian practice in Las Relaciones geográficas de Indias. Spanish domination led to a change in the eating habits of the indigenous peoples, only has interest in using lupins as a food been renewed.
Lupins can be used to make a variety of foods both sweet and savoury, including everyday meals, traditional fermented foods, baked foods, sauces. The European white lupin beans are sold in a salty solution in jars and can be eaten with or without the skin. Lupini dishes are most found in Europe in Portugal, Spain and Italy, they are common in Brazil and Egypt. In Egypt, the lupin is known in Arabic as ترمس termes, is a popular street snack after being treated with several soakings of water, brined. In Portugal and Spanish Harlem, they are consumed with beer. In Lebanon, Syria and Israel, salty and chilled lupini beans are called termos and in Hebrew turmus and are served as part of an apéritif or a snack. Other species, such as L. albus, L. angustifolius, L. hirsutus have edible seeds. Some lupins contain certain secondary compounds, including isoflavones and toxic alkaloids, such as lupinine and sparteine. With early detection, these can be removed through processing, although lupins containing these elements are not selected for food-grade products.
A risk of lupine allergy exists in patients allergic to peanuts. Indeed, most lupin reactions reported; because of the cross-allergenicity of peanut and lupin, the European Commission, as of 2006, has required that food labels indicate the presence of "lupin and products thereof" in food. Many annual species of lupins are used in agriculture and most of them have Mediterranean origin. While cultivated as a green manure or forage, lupins are grown for their seeds, which can be used as an alternative to soybeans. Sweet lupins are regarded as a stock feed for ruminants, but for pigs and poultry and more as an ingredient in aqua-feeds; the market for lupin seeds for human food is small, but researchers believe it has great potential. Lupin seeds are considered "superior" to soybeans in certain applications and evidence is increasing for their potential health benefits, they less fat. As a food source, they are gluten-free and high in dietary fiber, amino acids, antioxidants, they are considered to be prebiotic.
About 85% of the world's lupin seeds are grown in Western Australia. Three Mediterranean species of lupin, blue lupin, white lupin, yellow lupin, are cultivated for livestock and poultry feed. Like other legumes, they can fix nitrogen from the atmosphere into ammonia via a rhizobium–root nodule symbiosis, fertilizing the soil for other plants; this adaption allows lupins to be tolerant of infertile soils and capable of pioneering change in barren and poor-quality soils. The genus Lupinus is nodulated by Bradyrhizobium soil bacteria. Lupinus polyphyllus, the garden lupin, Lupinus arboreus, the tree lupin, are popular ornamental plants in gardens, are the source of numerous hybrids and cultivars in a wide range of colours, including bicolors; as legumes, lupins are good companion plants in gardens, increasing the soil nitrogen for vegetables and other plants. Certain species, such as the yellow bush lupin, are considered invasive weeds
Europe is a continent located in the Northern Hemisphere and in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west and the Mediterranean Sea to the south, it comprises the westernmost part of Eurasia. Since around 1850, Europe is most considered to be separated from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas and the waterways of the Turkish Straits. Although the term "continent" implies physical geography, the land border is somewhat arbitrary and has been redefined several times since its first conception in classical antiquity; the division of Eurasia into two continents reflects East-West cultural and ethnic differences which vary on a spectrum rather than with a sharp dividing line. The geographic border does not follow political boundaries, with Turkey and Kazakhstan being transcontinental countries. A strict application of the Caucasus Mountains boundary places two comparatively small countries and Georgia, in both continents.
Europe covers 2 % of the Earth's surface. Politically, Europe is divided into about fifty sovereign states of which the Russian Federation is the largest and most populous, spanning 39% of the continent and comprising 15% of its population. Europe had a total population of about 741 million as of 2016; the European climate is affected by warm Atlantic currents that temper winters and summers on much of the continent at latitudes along which the climate in Asia and North America is severe. Further from the sea, seasonal differences are more noticeable than close to the coast. Europe, in particular ancient Greece, was the birthplace of Western civilization; the fall of the Western Roman Empire in 476 AD and the subsequent Migration Period marked the end of ancient history and the beginning of the Middle Ages. Renaissance humanism, exploration and science led to the modern era. Since the Age of Discovery started by Portugal and Spain, Europe played a predominant role in global affairs. Between the 16th and 20th centuries, European powers controlled at various times the Americas all of Africa and Oceania and the majority of Asia.
The Age of Enlightenment, the subsequent French Revolution and the Napoleonic Wars shaped the continent culturally and economically from the end of the 17th century until the first half of the 19th century. The Industrial Revolution, which began in Great Britain at the end of the 18th century, gave rise to radical economic and social change in Western Europe and the wider world. Both world wars took place for the most part in Europe, contributing to a decline in Western European dominance in world affairs by the mid-20th century as the Soviet Union and the United States took prominence. During the Cold War, Europe was divided along the Iron Curtain between NATO in the West and the Warsaw Pact in the East, until the revolutions of 1989 and fall of the Berlin Wall. In 1949 the Council of Europe was founded, following a speech by Sir Winston Churchill, with the idea of unifying Europe to achieve common goals, it includes all European states except for Belarus and Vatican City. Further European integration by some states led to the formation of the European Union, a separate political entity that lies between a confederation and a federation.
The EU originated in Western Europe but has been expanding eastward since the fall of the Soviet Union in 1991. The currency of most countries of the European Union, the euro, is the most used among Europeans. In classical Greek mythology, Europa was a Phoenician princess; the word Europe is derived from her name. The name contains the elements εὐρύς, "wide, broad" and ὤψ "eye, countenance", hence their composite Eurṓpē would mean "wide-gazing" or "broad of aspect". Broad has been an epithet of Earth herself in the reconstructed Proto-Indo-European religion and the poetry devoted to it. There have been attempts to connect Eurṓpē to a Semitic term for "west", this being either Akkadian erebu meaning "to go down, set" or Phoenician'ereb "evening, west", at the origin of Arabic Maghreb and Hebrew ma'arav. Michael A. Barry, professor in Princeton University's Near Eastern Studies Department, finds the mention of the word Ereb on an Assyrian stele with the meaning of "night, sunset", in opposition to Asu " sunrise", i.e. Asia.
The same naming motive according to "cartographic convention" appears in Greek Ἀνατολή. Martin Litchfield West stated that "phonologically, the match between Europa's name and any form of the Semitic word is poor." Next to these hypotheses there is a Proto-Indo-European root *h1regʷos, meaning "darkness", which produced Greek Erebus. Most major world languages use words derived from Europa to refer to the continent. Chinese, for example, uses the word Ōuzhōu. In some Turkic languages the Persian name Frangistan is used casually in referring to much of Europe, besides official names such as Avrupa or Evropa; the prevalent definition of Europe as a geographical term has been in use since the mid-19th century. Europe is taken to be bounded by large bodies of water