A bog or bogland is a wetland that accumulates peat, a deposit of dead plant material—often mosses, in a majority of cases, sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire and muskeg, they are covered in ericaceous shrubs rooted in the sphagnum moss and peat. The gradual accumulation of decayed plant material in a bog functions as a carbon sink. Bogs occur where the water at the ground surface is low in nutrients. In some cases, the water is derived from precipitation, in which case they are termed ombrotrophic. Water flowing out of bogs has a characteristic brown colour, which comes from dissolved peat tannins. In general, the low fertility and cool climate result in slow plant growth, but decay is slower owing to the saturated soil. Hence, peat accumulates. Large areas of the landscape can be covered many meters deep in peat. Bogs have distinctive assemblages of animal and plant species, are of high importance for biodiversity in landscapes that are otherwise settled and farmed.
Bogs are distributed in cold, temperate climes in boreal ecosystems in the Northern Hemisphere. The world's largest wetland is the peat bogs of the Western Siberian Lowlands in Russia, which cover more than a million square kilometres. Large peat bogs occur in North America the Hudson Bay Lowland and the Mackenzie River Basin, they are less common in the Southern Hemisphere, with the largest being the Magellanic moorland, comprising some 44,000 square kilometres. Sphagnum bogs were widespread in northern Europe but have been cleared and drained for agriculture. A 2014 expedition leaving from Itanga village, Republic of the Congo, discovered a peat bog "as big as England" which stretches into neighboring Democratic Republic of Congo. There are many specialised animals and plants associated with bog habitat. Most are capable of waterlogging. Sphagnum is abundant, along with ericaceous shrubs; the shrubs are evergreen, understood to assist in conservation of nutrients. In drier locations, evergreen trees can occur, in which case the bog blends into the surrounding expanses of boreal evergreen forest.
Sedges are one of the more common herbaceous species. Carnivorous plants such as sundews and pitcher plants have adapted to the low-nutrient conditions by using invertebrates as a nutrient source. Orchids have adapted to these conditions through the use of mycorrhizal fungi to extract nutrients; some shrubs such as Myrica gale have root nodules in which nitrogen fixation occurs, thereby providing another supplemental source of nitrogen. Bogs are recognized as a significant/specific habitat type by a number of governmental and conservation agencies, they can provide habitat for mammals, such as caribou and beavers, as well as for species of nesting shorebirds, such as Siberian cranes and yellowlegs. The United Kingdom in its Biodiversity Action Plan establishes bog habitats as a priority for conservation. Russia has a large reserve system in the West Siberian Lowland; the highest protected status occurs in Zapovedniks. Bogs have distinctive insects. In Ireland, the viviparous lizard, the only known reptile in the country, dwells in bogland.
Bog habitats may develop depending on the climate and topography. One way of classifying bogs is based upon their location in the landscape, their source of water; these develop in sloping valleys or hollows. A layer of peat fills the deepest part of the valley, a stream may run through the surface of the bog. Valley bogs may develop in dry and warm climates, but because they rely on ground or surface water, they only occur on acidic substrates; these develop over either non-acidic or acidic substrates. Over centuries there is a progression from open lake, to a marsh, to a fen, to a carr, as silt or peat accumulates within the lake. Peat builds up to a level where the land surface is too flat for ground or surface water to reach the center of the wetland; this part, becomes wholly rain-fed, the resulting acidic conditions allow the development of bog. The bog continues to form peat, over time a shallow dome of bog peat develops into a raised bog; the dome is a few meters high in the center and is surrounded by strips of fen or other wetland vegetation at the edges or along streamsides where groundwater can percolate into the wetland.
The various types of raised bog may be divided into: Coastal bog Plateau bog Upland bog Kermi bog String bog Palsa bog Polygonal bog In cool climates with high rainfall, the ground surface may remain waterlogged for much of the time, providing conditions for the development of bog vegetation. In these circumstances, bog develops as a layer "blanketing" much of the land, including hilltops and slopes. Although a blanket bog is more common on acidic substrates, under some conditions it may develop on neutral or alkaline ones, if abundant acidic rainwater predominates over the groundwater. A blanket bog cannot occur in drier or warmer climates, because under those conditions hilltops and sloping ground dry out
Missouri Botanical Garden
The Missouri Botanical Garden is a botanical garden located at 4344 Shaw Boulevard in St. Louis, Missouri, it is known informally as Shaw's Garden for founder and philanthropist Henry Shaw. Its herbarium, with more than 6.6 million specimens, is the second largest in North America, behind only that of the New York Botanical Garden. Founded in 1859, the Missouri Botanical Garden is one of the oldest botanical institutions in the United States and a National Historic Landmark, it is listed in the National Register of Historic Places. The Garden is a center for botanical research and science education of international repute, as well as an oasis in the city of St. Louis, with 79 acres of horticultural display, it includes a 14-acre Japanese strolling garden named Seiwa-en. It is adjacent to another of Shaw's legacies. In 1983, the Botanical Garden was added as the fourth subdistrict of the Metropolitan Zoological Park and Museum District. For part of 2006, the Missouri Botanical Garden featured "Glass in the Garden", with glass sculptures by Dale Chihuly placed throughout the garden.
Four pieces were purchased to remain at the gardens. In 2008 sculptures of the French artist Niki de Saint Phalle were placed throughout the garden. In 2009, the 150th anniversary of the Garden was celebrated, including a floral clock display. After 40 years of service to the Garden, Dr. Peter Raven retired from his presidential post on September 1, 2010. Dr. Peter Wyse Jackson replaced him as President; the Garden is a place for many annual cultural festivals, including the Japanese Festival and the Chinese Culture Days by the St. Louis Chinese Culture Days Committee. During this time, there are showcases of the culture's botanics as well as cultural arts, crafts and food; the Japanese Festival features sumo wrestling, taiko drumming, koma-mawashi top spinning, kimono fashion shows. The Garden is known for its bonsai growing, which can be seen all year round, but is highlighted during the multiple Asian festivals. Major garden features include: Tower Grove House and Herb Garden - Shaw's Victorian country house designed by prominent local architect George I.
Barnett in the Italianate style. Victory of Science Over Ignorance - Marble statue by Carlo Nicoli. Linnean House - Said to be the oldest continually operated greenhouse west of the Mississippi River. Shaw's orangery, in the late 1930s it was converted to house camellias. Gladney Rose Garden - Circular rose garden with arbors. Climatron and Reflecting Pools - the world's first geodesic dome greenhouse designed by architect and engineer Thomas C. Howard of Synergetics, Inc. English Woodland Garden - aconite, bluebells, hosta and others beneath the tree canopy. Seiwa-en Japanese Garden - is a 14-acre chisen kaiyu-shiki with lawns and path set around a 4-acre central lake, it is the largest Japanese Garden in North America. Grigg Nanjing Friendship Chinese Garden - Designed by architect Yong Pan. Blanke Boxwood Garden - walled parterre with a fine boxwood collection. Strassenfest German Garden - flora native to Germany and Central Europe. Ottoman garden with water xeriscape. Douglas Trumbull, director of the 1972 science fiction classic film Silent Running, stated that the geodesic domes on the spaceship Valley Forge were based on the Missouri Botanical Garden's Climatron dome.
Missouri Botanical Garden operates the Sophia M. Sachs Butterfly House in Chesterfield; the Butterfly House includes an 8,000-square-foot indoor butterfly conservatory as well as an outdoor butterfly garden. The EarthWays Center is a group at the Missouri Botanical Garden that provides resources on and educates the public about green practices, renewable energy, energy efficiency, other sustainability matters; the Shaw Nature Reserve was started by the Missouri Botanical Garden in 1925 as a place to store plants away from the pollution of the city. The air in St. Louis cleared up, the reserve has continued to be open to the public for enjoyment and education since; the 2,400-acre reserve is located in Missouri, 35 miles away from the city. The Plant List is an Internet encyclopedia project to compile a comprehensive list of botanical nomenclature, created by the Royal Botanic Gardens and the Missouri Botanical Garden; the Plant List has 1,040,426 scientific plant names of species rank, of which 298,900 are accepted species names.
In addition, the list has 16,167 plant genera. Monsanto has donated $10 million to the Missouri Botanical Garden since the 1970s, which named its 1998 plant science facility the'Monsanto Center'. List of botanical gardens in the United States Peter F. Stevens, a biologist working in the Missouri Botanical Garden Annals of the Missouri Botanical Garden, journal St. Louis Chinese Culture Day List of National Historic Landmarks in Missouri N
Canada is a country in the northern part of North America. Its ten provinces and three territories extend from the Atlantic to the Pacific and northward into the Arctic Ocean, covering 9.98 million square kilometres, making it the world's second-largest country by total area. Canada's southern border with the United States is the world's longest bi-national land border, its capital is Ottawa, its three largest metropolitan areas are Toronto and Vancouver. As a whole, Canada is sparsely populated, the majority of its land area being dominated by forest and tundra, its population is urbanized, with over 80 percent of its inhabitants concentrated in large and medium-sized cities, many near the southern border. Canada's climate varies across its vast area, ranging from arctic weather in the north, to hot summers in the southern regions, with four distinct seasons. Various indigenous peoples have inhabited what is now Canada for thousands of years prior to European colonization. Beginning in the 16th century and French expeditions explored, settled, along the Atlantic coast.
As a consequence of various armed conflicts, France ceded nearly all of its colonies in North America in 1763. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces; this began an accretion of provinces and territories and a process of increasing autonomy from the United Kingdom. This widening autonomy was highlighted by the Statute of Westminster of 1931 and culminated in the Canada Act of 1982, which severed the vestiges of legal dependence on the British parliament. Canada is a parliamentary democracy and a constitutional monarchy in the Westminster tradition, with Elizabeth II as its queen and a prime minister who serves as the chair of the federal cabinet and head of government; the country is a realm within the Commonwealth of Nations, a member of the Francophonie and bilingual at the federal level. It ranks among the highest in international measurements of government transparency, civil liberties, quality of life, economic freedom, education.
It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many other countries. Canada's long and complex relationship with the United States has had a significant impact on its economy and culture. A developed country, Canada has the sixteenth-highest nominal per capita income globally as well as the twelfth-highest ranking in the Human Development Index, its advanced economy is the tenth-largest in the world, relying chiefly upon its abundant natural resources and well-developed international trade networks. Canada is part of several major international and intergovernmental institutions or groupings including the United Nations, the North Atlantic Treaty Organization, the G7, the Group of Ten, the G20, the North American Free Trade Agreement and the Asia-Pacific Economic Cooperation forum. While a variety of theories have been postulated for the etymological origins of Canada, the name is now accepted as coming from the St. Lawrence Iroquoian word kanata, meaning "village" or "settlement".
In 1535, indigenous inhabitants of the present-day Quebec City region used the word to direct French explorer Jacques Cartier to the village of Stadacona. Cartier used the word Canada to refer not only to that particular village but to the entire area subject to Donnacona. From the 16th to the early 18th century "Canada" referred to the part of New France that lay along the Saint Lawrence River. In 1791, the area became two British colonies called Upper Canada and Lower Canada collectively named the Canadas. Upon Confederation in 1867, Canada was adopted as the legal name for the new country at the London Conference, the word Dominion was conferred as the country's title. By the 1950s, the term Dominion of Canada was no longer used by the United Kingdom, which considered Canada a "Realm of the Commonwealth"; the government of Louis St. Laurent ended the practice of using'Dominion' in the Statutes of Canada in 1951. In 1982, the passage of the Canada Act, bringing the Constitution of Canada under Canadian control, referred only to Canada, that year the name of the national holiday was changed from Dominion Day to Canada Day.
The term Dominion was used to distinguish the federal government from the provinces, though after the Second World War the term federal had replaced dominion. Indigenous peoples in present-day Canada include the First Nations, Métis, the last being a mixed-blood people who originated in the mid-17th century when First Nations and Inuit people married European settlers; the term "Aboriginal" as a collective noun is a specific term of art used in some legal documents, including the Constitution Act 1982. The first inhabitants of North America are hypothesized to have migrated from Siberia by way of the Bering land bridge and arrived at least 14,000 years ago; the Paleo-Indian archeological sites at Old Crow Flats and Bluefish Caves are two of the oldest sites of human habitation in Canada. The characteristics of Canadian indigenous societies included permanent settlements, complex societal hierarchies, trading networks; some of these cultures had collapsed by the time European explorers arrived in the late 15th and early 16th centuries and have only been discovered through archeological investigations.
The indigenous population at the time of the first European settlements is estimated to have been between 200,000
In botany, the petiole is the stalk that attaches the leaf blade to the stem. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves lacking a petiole are called epetiolate; the petiole is a stalk. In petiolate leaves, the leaf stalk may be long, as in the leaves of celery and rhubarb, short or absent, in which case the blade attaches directly to the stem and is said to be sessile. Subpetiolate leaves are nearly petiolate, or have an short petiole, may appear sessile; the broomrape family Orobanchaceae is an example of a family. In some other plant groups, such as the speedwell genus Veronica and sessile leaves may occur in different species. In the grasses the leaves are apetiolate, but the leaf blade may be narrowed at the junction with the leaf sheath to form a pseudopetiole, as in Pseudosasa japonica. In plants with compound leaves, the leaflets are attached to a continuation of the petiole called the rachis; each leaflet may be attached to the rachis by a short stalk called the petiolule.
There may be swollen regions at either end of the petiole known as pulvina that are composed of a flexible tissue that allows leaf movement. Pulvina are common in the prayer plant family Marantaceae. A pulvinus on a petiolule is called a pulvinulus. In some plants, the petioles are flattened and widened, to become phyllodes or phyllodia, or cladophylls and the true leaves may be reduced or absent. Thus, the phyllode comes to serve the functions of the leaf. Phyllodes are common in the genus Acacia the Australian species, at one time put in Acacia subgenus Phyllodineae. In Acacia koa, the phyllodes are leathery and thick, allowing the tree to survive stressful environments; the petiole allows submerged hydrophytes to have leaves floating at different depths, the petiole being between the node and the stem. In plants such as rhubarb, celery and cardoons the petioles are cultivated as edible crops; the petiole of rhubarb produces the leaf at its end. Botanically it is culinarily used as a fruit. Petiole comes from Latin petiolus, or peciolus "little foot", "stem", an alternative diminutive of pes "foot".
The regular diminutive pediculus is used for "foot stalk". Hyponastic response Pedicel "Petiole". Collier's New Encyclopedia. 1921
In botany, a berry is a fleshy fruit without a stone produced from a single flower containing one ovary. Berries so defined include grapes and tomatoes, as well as cucumbers and bananas, but exclude certain fruits called berries, such as strawberries and raspberries; the berry is the most common type of fleshy fruit in which the entire outer layer of the ovary wall ripens into a edible "pericarp". Berries may be formed from one or more carpels from the same flower; the seeds are embedded in the fleshy interior of the ovary, but there are some non-fleshy exceptions, such as peppers, with air rather than pulp around their seeds. Many berries are edible, but others, such as the fruits of the potato and the deadly nightshade, are poisonous to humans. A plant that bears berries is said to be baccate. In everyday English, a "berry" is any small edible fruit. Berries are juicy, brightly coloured, sweet or sour, do not have a stone or pit, although many pips or seeds may be present. In botanical language, a berry is a simple fruit having seeds and fleshy pulp produced from the ovary of a single flower.
The ovary can be superior. It is indehiscent, i.e. it does not have a special "line of weakness" along which it splits to release the seeds when ripe. The pericarp is divided into three layers; the outer layer is called the "exocarp" or "epicarp". Botanists have not applied these terms consistently. Exocarp and endocarp may be restricted to more-or-less single-layered "skins", or may include tissues adjacent to them; the inconsistency in usage has been described as "a source of confusion". The nature of the endocarp distinguishes a berry from a drupe, which has a hardened or stony endocarp; the two kinds of fruit intergrade, depending on the state of the endocarp. Some sources have attempted to quantify the difference, e.g. requiring the endocarp to be less than 2 mm thick in a berry. Examples of botanical berries include: "True berries", or "baccae", may be required to have a thin outer skin, not self-supporting when removed from the berry; this distinguishes, for example, a Vaccinium or Solanum berry from an Adansonia amphisarca, which has a dry, more rigid and self-supporting skin.
The fruit of citrus, such as the orange and lemon, is a berry with a thick rind and a juicy interior divided into segments by septa, given the special name "hesperidium". A specialized term, pepo, is used for fruits of the gourd family Cucurbitaceae, which are modified to have a hard outer rind, but are not internally divided by septae; the fruits of Passiflora and Carica are sometimes considered pepos. Berries that develop from an inferior ovary are sometimes termed epigynous berries or false berries, as opposed to true berries, which develop from a superior ovary. In epigynous berries, the berry includes tissue derived from parts of the flower besides the ovary; the floral tube, formed from the basal part of the sepals and stamens can become fleshy at maturity and is united with the ovary to form the fruit. Common fruits that are sometimes classified as epigynous berries include bananas, members of the genus Vaccinium, members of the family Cucurbitaceae. Many fruits referred to as berries are not actual berries by the scientific definition, but fall into one of the following categories: Drupes are fleshy fruits produced from a single-seeded ovary with a hard woody layer surrounding the seed.
Familiar examples include the stonefruits of the genus Prunus, coconut and Persea species. Some definitions make the mere presence of an internally differentiated endocarp the defining feature of a drupe; the term "drupaceous" is used of fruits that have the general structure and texture of a drupe, without meeting the full definition. Other drupe-like fruits with a single seed that lack the stony endocarp include sea-buckthorn, an achene, surrounded by a swollen hypanthium that provides the fleshy layer. Fruits of Coffea species are described as either berries; the pome fruits produced by plants in subtribe Pyrinae of family Rosaceae, such as apples and pears, have a structure in which tough tissue separates the seeds from the outer softer pericarp. However, some of the smaller pomes are sometimes referred to as berries. Amelanchier pomes become so soft at maturity that they resemble a blueberry and are known as Juneberries, serviceberries or Saskatoon berries. Aggregate or compound fruits contain seeds from different ovaries of a single flower, with the individual "fruitlets" joined together at maturity to form the complete fruit.
Examples of aggregate fruits called "berries" include members of the genus Rubus, such as blackberry and raspberry. Other large aggregate fruits, such as soursop, are not called "berries", although some sources do use this term. Multiple fruits are the fruits of two or more multiple flowers that are merged or packed together; the mulberry is a berry-like example of a multiple fruit.
In botany and dendrology, a rhizome is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are called creeping rootstalks or just rootstalks. Rhizomes grow horizontally; the rhizome retains the ability to allow new shoots to grow upwards. A rhizome is the main stem of the plant. A stolon is similar to a rhizome, but a stolon sprouts from an existing stem, has long internodes, generates new shoots at the end, such as in the strawberry plant. In general, rhizomes have short internodes, send out roots from the bottom of the nodes, generate new upward-growing shoots from the top of the nodes. A stem tuber is a thickened part of a rhizome or stolon, enlarged for use as a storage organ. In general, a tuber is high in starch, e.g. the potato, a modified stolon. The term "tuber" is used imprecisely and is sometimes applied to plants with rhizomes. If a rhizome is separated each piece may be able to give rise to a new plant; the plant uses the rhizome to store starches and other nutrients.
These nutrients become useful for the plant when new shoots must be formed or when the plant dies back for the winter. This is a process known as vegetative reproduction and is used by farmers and gardeners to propagate certain plants; this allows for lateral spread of grasses like bamboo and bunch grasses. Examples of plants that are propagated this way include hops, ginger, lily of the valley and sympodial orchids; some rhizomes which are used directly in cooking include ginger, galangal and lotus. Stored rhizomes are subject to bacterial and fungal infections, making them unsuitable for replanting and diminishing stocks. However, rhizomes can be produced artificially from tissue cultures; the ability to grow rhizomes from tissue cultures leads to better stocks for replanting and greater yields. The plant hormones ethylene and jasmonic acid have been found to help induce and regulate the growth of rhizomes in rhubarb. Ethylene, applied externally was found to affect internal ethylene levels, allowing easy manipulations of ethylene concentrations.
Knowledge of how to use these hormones to induce rhizome growth could help farmers and biologists producing plants grown from rhizomes more cultivate and grow better plants. Some plants have rhizomes that grow above ground or that lie at the soil surface, including some Iris species, ferns, whose spreading stems are rhizomes. Plants with underground rhizomes include gingers, the Venus flytrap, Chinese lantern, western poison-oak and Alstroemeria, the weeds Johnson grass, Bermuda grass, purple nut sedge. Rhizomes form a single layer, but in giant horsetails, can be multi-tiered. Many rhizomes have culinary value, some, such as zhe'ergen, are consumed raw. Aspen Corm Mycorrhiza Media related to Rhizomes at Wikimedia Commons The Rhizome Collective for sustainable living
Asia is Earth's largest and most populous continent, located in the Eastern and Northern Hemispheres. It shares the continental landmass of Eurasia with the continent of Europe and the continental landmass of Afro-Eurasia with both Europe and Africa. Asia covers an area of 44,579,000 square kilometres, about 30% of Earth's total land area and 8.7% of the Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Asia is notable for not only its overall large size and population, but dense and large settlements, as well as vast populated regions, its 4.5 billion people constitute 60% of the world's population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, on the north by the Arctic Ocean; the border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It has moved since its first conception in classical antiquity.
The division of Eurasia into two continents reflects East–West cultural and ethnic differences, some of which vary on a spectrum rather than with a sharp dividing line. The most accepted boundaries place Asia to the east of the Suez Canal separating it from Africa. China and India alternated in being the largest economies in the world from 1 to 1800 CE. China was a major economic power and attracted many to the east, for many the legendary wealth and prosperity of the ancient culture of India personified Asia, attracting European commerce and colonialism; the accidental discovery of a trans-Atlantic route from Europe to America by Columbus while in search for a route to India demonstrates this deep fascination. The Silk Road became the main east–west trading route in the Asian hinterlands while the Straits of Malacca stood as a major sea route. Asia has exhibited economic dynamism as well as robust population growth during the 20th century, but overall population growth has since fallen. Asia was the birthplace of most of the world's mainstream religions including Hinduism, Judaism, Buddhism, Taoism, Islam, Sikhism, as well as many other religions.
Given its size and diversity, the concept of Asia—a name dating back to classical antiquity—may have more to do with human geography than physical geography. Asia varies across and within its regions with regard to ethnic groups, environments, historical ties and government systems, it has a mix of many different climates ranging from the equatorial south via the hot desert in the Middle East, temperate areas in the east and the continental centre to vast subarctic and polar areas in Siberia. The boundary between Asia and Africa is the Red Sea, the Gulf of Suez, the Suez Canal; this makes Egypt a transcontinental country, with the Sinai peninsula in Asia and the remainder of the country in Africa. The border between Asia and Europe was defined by European academics; the Don River became unsatisfactory to northern Europeans when Peter the Great, king of the Tsardom of Russia, defeating rival claims of Sweden and the Ottoman Empire to the eastern lands, armed resistance by the tribes of Siberia, synthesized a new Russian Empire extending to the Ural Mountains and beyond, founded in 1721.
The major geographical theorist of the empire was a former Swedish prisoner-of-war, taken at the Battle of Poltava in 1709 and assigned to Tobolsk, where he associated with Peter's Siberian official, Vasily Tatishchev, was allowed freedom to conduct geographical and anthropological studies in preparation for a future book. In Sweden, five years after Peter's death, in 1730 Philip Johan von Strahlenberg published a new atlas proposing the Urals as the border of Asia. Tatishchev announced; the latter had suggested the Emba River as the lower boundary. Over the next century various proposals were made until the Ural River prevailed in the mid-19th century; the border had been moved perforce from the Black Sea to the Caspian Sea into which the Ural River projects. The border between the Black Sea and the Caspian is placed along the crest of the Caucasus Mountains, although it is sometimes placed further north; the border between Asia and the region of Oceania is placed somewhere in the Malay Archipelago.
The Maluku Islands in Indonesia are considered to lie on the border of southeast Asia, with New Guinea, to the east of the islands, being wholly part of Oceania. The terms Southeast Asia and Oceania, devised in the 19th century, have had several vastly different geographic meanings since their inception; the chief factor in determining which islands of the Malay Archipelago are Asian has been the location of the colonial possessions of the various empires there. Lewis and Wigen assert, "The narrowing of'Southeast Asia' to its present boundaries was thus a gradual process." Geographical Asia is a cultural artifact of European conceptions of the world, beginning with the Ancient Greeks, being imposed onto other cultures, an imprecise concept causing endemic contention about what it means. Asia does not correspond to the cultural borders of its various types of constituents. From the time of Herodotus a minority of geographers have rejected the three-continent system on the grounds that there is no substantial physical separation between