South America is a continent in the Western Hemisphere in the Southern Hemisphere, with a small portion in the Northern Hemisphere. It may be considered a subcontinent of the Americas, how it is viewed in the Spanish and Portuguese-speaking regions of the Americas; the reference to South America instead of other regions has increased in the last decades due to changing geopolitical dynamics. It is bordered on the west on the north and east by the Atlantic Ocean, it includes twelve sovereign states, a part of France, a non-sovereign area. In addition to this, the ABC islands of the Kingdom of the Netherlands and Tobago, Panama may be considered part of South America. South America has an area of 17,840,000 square kilometers, its population as of 2016 has been estimated at more than 420 million. South America ranks fourth in fifth in population. Brazil is by far the most populous South American country, with more than half of the continent's population, followed by Colombia, Argentina and Peru. In recent decades Brazil has concentrated half of the region's GDP and has become a first regional power.
Most of the population lives near the continent's western or eastern coasts while the interior and the far south are sparsely populated. The geography of western South America is dominated by the Andes mountains. Most of the continent lies in the tropics; the continent's cultural and ethnic outlook has its origin with the interaction of indigenous peoples with European conquerors and immigrants and, more locally, with African slaves. Given a long history of colonialism, the overwhelming majority of South Americans speak Portuguese or Spanish, societies and states reflect Western traditions. South America occupies the southern portion of the Americas; the continent is delimited on the northwest by the Darién watershed along the Colombia–Panama border, although some may consider the border instead to be the Panama Canal. Geopolitically and geographically all of Panama – including the segment east of the Panama Canal in the isthmus – is included in North America alone and among the countries of Central America.
All of mainland South America sits on the South American Plate. South America is home to Angel Falls in Venezuela. South America's major mineral resources are gold, copper, iron ore and petroleum; these resources found in South America have brought high income to its countries in times of war or of rapid economic growth by industrialized countries elsewhere. However, the concentration in producing one major export commodity has hindered the development of diversified economies; the fluctuation in the price of commodities in the international markets has led to major highs and lows in the economies of South American states causing extreme political instability. This is leading to efforts to diversify production to drive away from staying as economies dedicated to one major export. South America is one of the most biodiverse continents on earth. South America is home to many interesting and unique species of animals including the llama, piranha, vicuña, tapir; the Amazon rainforests possess high biodiversity, containing a major proportion of the Earth's species.
Brazil is the largest country in South America, encompassing around half of the continent's land area and population. The remaining countries and territories are divided among three regions: The Andean States, the Guianas and the Southern Cone. Traditionally, South America includes some of the nearby islands. Aruba, Curaçao, Trinidad and the federal dependencies of Venezuela sit on the northerly South American continental shelf and are considered part of the continent. Geo-politically, the island states and overseas territories of the Caribbean are grouped as a part or subregion of North America, since they are more distant on the Caribbean Plate though San Andres and Providencia are politically part of Colombia and Aves Island is controlled by Venezuela. Other islands that are included with South America are the Galápagos Islands that belong to Ecuador and Easter Island, Robinson Crusoe Island, Chiloé and Tierra del Fuego. In the Atlantic, Brazil owns Fernando de Noronha and Martim Vaz, the Saint Peter and Saint Paul Archipelago, while the Falkland Islands are governed by the United Kingdom, whose sovereignty over the islands is disputed by Argentina.
South Georgia and the South Sandwich Islands may be associate
Binomial nomenclature called binominal nomenclature or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomen, binominal name or a scientific name; the first part of the name – the generic name – identifies the genus to which the species belongs, while the second part – the specific name or specific epithet – identifies the species within the genus. For example, humans belong within this genus to the species Homo sapiens. Tyrannosaurus rex is the most known binomial; the formal introduction of this system of naming species is credited to Carl Linnaeus beginning with his work Species Plantarum in 1753. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus; the application of binomial nomenclature is now governed by various internationally agreed codes of rules, of which the two most important are the International Code of Zoological Nomenclature for animals and the International Code of Nomenclature for algae and plants.
Although the general principles underlying binomial nomenclature are common to these two codes, there are some differences, both in the terminology they use and in their precise rules. In modern usage, the first letter of the first part of the name, the genus, is always capitalized in writing, while that of the second part is not when derived from a proper noun such as the name of a person or place. Both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a binomial name is given, at least when it is first mentioned, the date of publication may be specified. In zoology "Patella vulgata Linnaeus, 1758"; the name "Linnaeus" tells the reader who it was that first published a description and name for this species of limpet. "Passer domesticus". The original name given by Linnaeus was Fringilla domestica; the ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, although nomenclatorial catalogs include such information.
In botany "Amaranthus retroflexus L." – "L." is the standard abbreviation used in botany for "Linnaeus". "Hyacinthoides italica Rothm. – Linnaeus first named this bluebell species Scilla italica. The name is composed of two word-forming elements: "bi", a Latin prefix for two, "-nomial", relating to a term or terms; the word "binomium" was used in Medieval Latin to mean a two-term expression in mathematics. Prior to the adoption of the modern binomial system of naming species, a scientific name consisted of a generic name combined with a specific name, from one to several words long. Together they formed a system of polynomial nomenclature; these names had two separate functions. First, to designate or label the species, second, to be a diagnosis or description. In a simple genus, containing only two species, it was easy to tell them apart with a one-word genus and a one-word specific name; such "polynomial names" may sometimes look like binomials, but are different. For example, Gerard's herbal describes various kinds of spiderwort: "The first is called Phalangium ramosum, Branched Spiderwort.
The other... is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia". The Latin phrases are short descriptions, rather than identifying labels; the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné, more known by his Latinized name Carl Linnaeus, it was in his 1753 Species Plantarum that he first began using a one-word "trivial name" together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as specific name; the Bauhins' genus names were retained in many of these, but the descriptive part was reduced to a single word. Linnaeus's trivial names introduced an important new idea, namely that the function of a name could be to give a species a unique label; this meant. Thus Gerard's Phalangium ephemerum virginianum became Tradescantia virgi
Arima The Royal Chartered Borough of Arima is the easternmost and second largest in area of the three boroughs of Trinidad and Tobago. It is geographically adjacent to Sangre Grande and Arouca at the southcentral foothills of the Northern Range. To the south is the Caroni–Arena Dam. Coterminous with Town of Arima since 1888, the borough of Arima is the fourth-largest municipality in population in the country; the census estimated it had 33,606 residents in 2011. In 1887, the town petitioned Queen Victoria for municipal status as part of her Golden Jubilee celebration; this was granted in the following year, Arima became a Royal Borough on 1 August 1888. The third-largest town of Trinidad and Tobago, Arima is fourth since Chaguanas became the largest town in the country; the borough has a tropical wet and dry climate climate characterised with little seasonal variations due to its close proximity to the Northern Range. Temperatures range from 19 to 33 degrees; the wet season lasts from June to November and the dry season lasts from December to May of the following year.
Hail is rare. Arima hosts an annual Borough Day anniversary celebration in August; the celebration incorporates Carnival-style street parades and coincides with the staging of the Santa Rosa Carib Community annual festival. The annual Arima Carnival includes street parades of masqueraders on Carnival Tuesday, J'ouvert bands on Carnival Monday, as well as a local calypso competition; the major land transportation arteries are the Churchill–Roosevelt Highway, Eastern Main Road and the Priority Bus Route which all link Arima with major towns and cities along the East–West Corridor metropolitan area. Among other important routes are the Arima Bypass, Cocorite Street, Tumpuna Road and O'Meara Road which links neighbourhoods around the town to the Town Center. Arima plays an important role for north-eastern Trinidad as a multi-modal transportation hub for many of the towns and neighbourhoods on the eastern side of the island. A bus terminal provides service by the PTSC Bus network to Sangre Grande, Mundo Nuevo, Carapo, Morne La Croix, La Horquetta, Brasso Seco and to the capital Port of Spain.
Maxi taxis operate throughout Tobago as a kind of semi-public transport. They operate along fixed routes, have fixed fares and meeting points, but do not operate under a fixed schedule; these maxi taxis provide services from the town center to Port of Spain via the Priority Bus Route and Churchill-Roosevelt Highway, making stops along the East–West Corridor. They provide transport to Sangre Grande; the major national super-league team, FC Santa Rosa and Arima Football League, based at the Arima Velodrome. Abilene Wildcats Athletic Club, Trinity College East Athletics Club, Silver Bullets Athletic Club, D'Abadie Progressive Athletic Club, Spartans High Speed Performance Athletic Club are based in Arima. Most suburbs and neighbourhoods around the Borough have their own sporting complexes and community swimming pools; the three major sporting arenas in Arima are: The Larry Gomes Stadium Arima Velodrome Santa Rosa Race Track Asa Wright Nature Centre, located in Arima Valley, it has a nature walk and swimming at a freshwater pond.
Santa Rosa Carib Centre, located on Paul Mitchell Road, off De Gannes Street in Arima, it contains items from Arima's native Carib history. It has displays about Carib descendants in Arima. Native items are available for purchase. Cleaver Woods, it has nature Amerindian exhibits. Electric generation is handled by Powergen, while electrical distribution is handled by the Trinidad and Tobago Electricity Commission. Powergen has natural gas fired generation plants at Point Lisas and Wrightson Road in Port of Spain. Additional power can be supplied from power generation facilities controlled by Inncogen at Point Lisas. Telecommunications are regulated by the Telecommunications Authority of Tobago, it has been working to break up the monopoly, granting several new licences in 2005 to new companies in the market. Fixed-line telephone service is a monopoly controlled by Telecommunications Services of Trinidad and Tobago. Licenses have been granted for competition in this area. Wireless telephony is controlled by bmobile, as well as Digicel, which came later.
Licenses have been granted for a private company, Laqtel, to offer wireless service in competition with TSTT and Digicel. However, Laqtel had its licence revoked, is undergoing severe financial difficulties. Digital cable television is provided by Flow. High speed internet service of up to 100Mbit/s and digital landline telephone service are all available in Arima. Water and sewerage are under the purview of the Sewerage Authority of Trinidad and Tobago. There are several primary and secondary educational institutions in Arima, some post-secondary level technical training institutes. St. Joseph's Convent in Arima was closed many years ago and the building now houses a retreat centre called Emmaus Centre. Schools Primary Arima Hindu Primary School Arima Boys' Government Primary School Arima Boys' R. C. Primary School Arima Centenary Government Primary School Arima Girls' Government Primary School Arima Girls' R. C. Primary School Arima New Government Primary School Arima Presbyterian Primary School Arima West Government Primary School Christian Primary Academy EdenWay Pre-Primary Christian School Giuseppi Preparatory Malabar Government Primary School Malabar R.
C. Primary School New Dawn Preparatory Santa Rosa Government Primary School St. Hilary's PreparatorySecondary Arima Governme
Peru the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, in the west by the Pacific Ocean. Peru is a megadiverse country with habitats ranging from the arid plains of the Pacific coastal region in the west to the peaks of the Andes mountains vertically extending from the north to the southeast of the country to the tropical Amazon Basin rainforest in the east with the Amazon river. Peruvian territory was home to several ancient cultures. Ranging from the Norte Chico civilization in the 32nd century BC, the oldest civilization in the Americas and one of the five cradles of civilization, to the Inca Empire, the largest state in pre-Columbian America, the territory now including Peru has one of the longest histories of civilization of any country, tracing its heritage back to the 4th millennia BCE; the Spanish Empire conquered the region in the 16th century and established a viceroyalty that encompassed most of its South American colonies, with its capital in Lima.
Peru formally proclaimed independence in 1821, following the military campaigns of José de San Martín and Simón Bolívar, the decisive battle of Ayacucho, Peru secured independence in 1824. In the ensuing years, the country enjoyed relative economic and political stability, which ended shortly before the War of the Pacific with Chile. Throughout the 20th century, Peru endured armed territorial disputes, social unrest, internal conflicts, as well as periods of stability and economic upswing. Alberto Fujimori was elected to the presidency in 1990. Fujimori left the presidency in 2000 and was charged with human rights violations and imprisoned until his pardon by President Pedro Pablo Kuczynski in 2017. After the president's regime, Fujimori's followers, called Fujimoristas, have caused political turmoil for any opposing faction in power causing Pedro Pablo Kuczynski to resign in March 2018; the sovereign state of Peru is a representative democratic republic divided into 25 regions. It is classified as an emerging market with a high level of human development and an upper middle income level with a poverty rate around 19 percent.
It is one of the region's most prosperous economies with an average growth rate of 5.9% and it has one of the world's fastest industrial growth rates at an average of 9.6%. Its main economic activities include mining, manufacturing and fishing; the country forms part of The Pacific Pumas, a political and economic grouping of countries along Latin America's Pacific coast that share common trends of positive growth, stable macroeconomic foundations, improved governance and an openness to global integration. Peru ranks high in social freedom. Peru has a population of 32 million, which includes Amerindians, Europeans and Asians; the main spoken language is Spanish, although a significant number of Peruvians speak Quechua or other native languages. This mixture of cultural traditions has resulted in a wide diversity of expressions in fields such as art, cuisine and music; the name of the country may be derived from Birú, the name of a local ruler who lived near the Bay of San Miguel, Panama City, in the early 16th century.
When his possessions were visited by Spanish explorers in 1522, they were the southernmost part of the New World yet known to Europeans. Thus, when Francisco Pizarro explored the regions farther south, they came to be designated Birú or Perú. An alternative history is provided by the contemporary writer Inca Garcilaso de la Vega, son of an Inca princess and a conquistador, he said the name Birú was that of a common Indian happened upon by the crew of a ship on an exploratory mission for governor Pedro Arias de Ávila, went on to relate more instances of misunderstandings due to the lack of a common language. The Spanish Crown gave the name legal status with the 1529 Capitulación de Toledo, which designated the newly encountered Inca Empire as the province of Peru. Under Spanish rule, the country adopted the denomination Viceroyalty of Peru, which became Republic of Peru after independence; the earliest evidences of human presence in Peruvian territory have been dated to 9,000 BC. Andean societies were based on agriculture, terracing.
Organization relied on reciprocity and redistribution because these societies had no notion of market or money. The oldest known complex society in Peru, the Norte Chico civilization, flourished along the coast of the Pacific Ocean between 3,000 and 1,800 BC; these early developments were followed by archaeological cultures that developed around the coastal and Andean regions throughout Peru. The Cupisnique culture which flourished from around 1000 to 200 BC along what is now Peru's Pacific Coast was an example of early pre-Incan culture; the Chavín culture that developed from 1500 to 300 BC was more of a religious than a political phenomenon, with their religious centre in Chavín de Huantar. After the decline of the Chavin culture around the beginning of the 1st century AD, a series of localized and specialized cultures rose and fell
Ecuador the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, the Pacific Ocean to the west. Ecuador includes the Galápagos Islands in the Pacific, about 1,000 kilometres west of the mainland; the capital city is Quito, the largest city. What is now Ecuador was home to a variety of Amerindian groups that were incorporated into the Inca Empire during the 15th century; the territory was colonized by Spain during the 16th century, achieving independence in 1820 as part of Gran Colombia, from which it emerged as its own sovereign state in 1830. The legacy of both empires is reflected in Ecuador's ethnically diverse population, with most of its 16.4 million people being mestizos, followed by large minorities of European and African descendants. Spanish is the official language and is spoken by a majority of the population, though 13 Amerindian languages are recognized, including Quichua and Shuar; the sovereign state of Ecuador is a middle-income representative democratic republic with a developing economy, dependent on commodities, namely petroleum and agricultural products.
It is governed as a democratic presidential republic. One of 18 megadiverse countries in the world, Ecuador hosts many endemic plants and animals, such as those of the Galápagos Islands. In recognition of its unique ecological heritage, the new constitution of 2008 is the first in the world to recognize enforceable Rights of Nature, or ecosystem rights, it has the fifth lowest homicide rate in the Americas. Various peoples had settled in the area of the future Ecuador before the arrival of the Incas; the archeological evidence suggests that the Paleo-Indians' first dispersal into the Americas occurred near the end of the last glacial period, around 16,500–13,000 years ago. The first Indians who reached Ecuador may have journeyed by land from North and Central America or by boat down the Pacific Ocean coastline. Much migrations to Ecuador may have come via the Amazon tributaries, others descended from northern South America, others ascended from the southern part of South America through the Andes.
They developed different languages while emerging as unique ethnic groups. Though their languages were unrelated, these groups developed similar groups of cultures, each based in different environments; the people of the coast developed a fishing and gathering culture. Over time these groups began to interact and intermingle with each other so that groups of families in one area became one community or tribe, with a similar language and culture. Many civilizations arose in Ecuador, such as the Valdivia Culture and Machalilla Culture on the coast, the Quitus, the Cañari; each civilization developed its own distinctive architecture and religious interests. In the highland Andes mountains, where life was more sedentary, groups of tribes cooperated and formed villages. Through wars and marriage alliances of their leaders, a group of nations formed confederations. One region consolidated under a confederation called the Shyris, which exercised organized trading and bartering between the different regions.
Its political and military power came under the rule of the Duchicela blood-line. When the Incas arrived, they found that these confederations were so developed that it took the Incas two generations of rulers—Topa Inca Yupanqui and Huayna Capac—to absorb them into the Inca Empire; the native confederations that gave them the most problems were deported to distant areas of Peru and north Argentina. A number of loyal Inca subjects from Peru and Bolivia were brought to Ecuador to prevent rebellion. Thus, the region of highland Ecuador became part of the Inca Empire in 1463 sharing the same language. In contrast, when the Incas made incursions into coastal Ecuador and the eastern Amazon jungles of Ecuador, they found both the environment and indigenous people more hostile. Moreover, when the Incas tried to subdue them, these indigenous people withdrew to the interior and resorted to guerrilla tactics; as a result, Inca expansion into the Amazon Basin and the Pacific coast of Ecuador was hampered.
The indigenous people of the Amazon jungle and coastal Ecuador remained autonomous until the Spanish soldiers and missionaries arrived in force. The Amazonian people and the Cayapas of Coastal Ecuador were the only groups to resist Inca and Spanish domination, maintaining their language and culture well into the 21st century. Before the arrival of the Spaniards, the Inca Empire was involved in a civil war; the untimely death of both the heir Ninan Cuchi and the Emperor Huayna Capac, from a European disease that spread into Ecuador, created a power vacuum between two factions. The northern faction headed by Atahualpa claims that Huayna Capac gave a verbal decree before his death about how the empire should be divided, he gave the territories pertaining to present-day Ecuador and northern Peru to his favorite son Atahualpa, to rule from Quito. He willed that his heart be buried in Quito, his favorite city, the rest of his body be buried with his ancestors in Cuzco. Huáscar did not recognize his fa
Hummingbirds are birds native to the Americas and constitute the biological family Trochilidae. They are among the smallest of most species measuring 7.5 -- 13 cm in length. The smallest extant bird species is a hummingbird, the 5 cm bee hummingbird weighing less than 2.0 g. They are known as hummingbirds because of the humming sound created by their beating wings which flap at high frequencies audible to humans, they hover in mid-air at rapid wing-flapping rates, which vary from around 12 beats per second in the largest species, to in excess of 80 in some of the smallest. Of those species that have been measured in wind tunnels, their top speed exceeds 15 m/s and some species can dive at speeds in excess of 22 m/s. Hummingbirds have the greatest mass-specific metabolic rate of any homeothermic animal. To conserve energy when food is scarce, nightly when not foraging, they can go into torpor, a state similar to hibernation, slowing metabolic rate to 1/15th of its normal rate. A map of the hummingbird family tree—reconstructed from analysis of 284 of the world's 338 known species—shows rapid diversification from 22 million years ago.
Hummingbirds fall into nine main clades, the Topazes, Mangoes, Coquettes, Mountain Gems and Emeralds, defining their relationship to nectar-bearing flowering plants and the birds' continued spread into new geographic areas. While all hummingbirds depend on flower nectar to fuel their high metabolisms and hovering flight, coordinated changes in flower- and bill shape stimulated the formation of new species of hummingbirds and plants. Due to this exceptional evolutionary pattern, as many as 140 hummingbird species can coexist in a specific region, such as the Andes range; the hummingbird evolutionary tree shows ancestral hummingbirds splitting from insectivorous swifts and treeswifts about 42 million years ago in Eurasia. One key evolutionary factor appears to be an altered taste receptor that enabled hummingbirds to seek nectar. By 22 million years ago the ancestral species of current hummingbirds became established in South America, where environmental conditions stimulated further diversification.
The Andes Mountains appear to be a rich environment for hummingbird evolution because diversification occurred with mountain uplift over the past 10 million years. Hummingbirds remain in dynamic diversification inhabiting ecological regions across South America, North America, the Caribbean, indicating an enlarging evolutionary radiation. Within the same geographic region, hummingbird clades co-evolved with nectar-bearing plant clades, affecting mechanisms of pollination; the same is true for the sword-billed hummingbird, one of the morphologically most extreme species, one of its main food plant clades. Hummingbirds exhibit sexual size dimorphism according to Rensch's rule, in which males are smaller than females in small species, males are larger than females in large-bodied species; the extent of this sexual size difference varies among clades of hummingbirds. For example, the Mellisugini clade exhibits a large size dimorphism, with females being larger than males. Conversely, the Lophomithini clade displays little size dimorphism.
Sexual dimorphisms in bill size and shape are present between male and female hummingbirds, where in many clades, females have longer, more curved bills favored for accessing nectar from tall flowers. For males and females of the same size, females will tend to have larger bills. Sexual size and bill differences evolved due to constraints imposed by courtship because mating displays of male hummingbirds require complex aerial maneuvers. Males tend to be smaller than females, allowing conservation of energy to forage competitively and participate more in courtship. Thus, sexual selection will favor smaller male hummingbirds. Female hummingbirds tend to be larger, requiring more energy, with longer beaks that allow for more effective reach into crevices of tall flowers for nectar, thus females are better at foraging, acquiring flower nectar, supporting the energy demands of their larger body size. Directional selection will thus favor the larger hummingbirds in terms of acquiring food. Another evolutionary cause of this sexual bill dimorphism is that the selective forces from competition for nectar between the sexes of each species are what drive the sexual dimorphism.
Depending on which sex holds territory in the species, it is advantageous for the other sex to have a longer bill and be able to feed on a wide variety of flowers, decreasing intraspecific competition. For example, in species of hummingbirds where males have longer bills, males do not hold a specific territory and have a lek mating system. In species where males have shorter bills than females, males defend their resources and therefore females must have a longer bill in order to feed from a broader range of flower. Hummingbirds are specialized nectarivores and are tied to the ornithophilous flowers upon which they feed; some species those with unusual bill shapes, such as the sword-billed hummingbird and the sicklebills, are co-evolved with a small number of flower species. The bee hummingbird – the world's smallest bird – evolved to dwarfism because it had to compete with long-billed hummingbirds having an advantage for nectar foraging from specialized flowers leading the bee hummingbird to more compete for flower foraging against insects.
Many plants pollinated by hummingbirds produce flowers in shades of red and bright pink, though the birds will take nectar from flowers of other colors
Monocotyledons referred to as monocots, are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided, the rest of the flowering plants having two cotyledons and therefore classified as dicotyledons, or dicots. However, molecular phylogenetic research has shown that while the monocots form a monophyletic group or clade, the dicots do not. Monocots have always been recognized as a group, but with various taxonomic ranks and under several different names; the APG III system of 2009 recognises a clade called "monocots" but does not assign it to a taxonomic rank. The monocots include about 60,000 species; the largest family in this group by number of species are the orchids, with more than 20,000 species. About half as many species belong to the true grasses, which are economically the most important family of monocots. In agriculture the majority of the biomass produced; these include not only major grains, but forage grasses, sugar cane, the bamboos.
Other economically important monocot crops include various palms and plantains, gingers and their relatives and cardamom, pineapple, water chestnut, leeks and garlic. Many houseplants are monocot epiphytes. Additionally most of the horticultural bulbs, plants cultivated for their blooms, such as lilies, irises, cannas and tulips, are monocots; the monocots or monocotyledons have, as the name implies, a single cotyledon, or embryonic leaf, in their seeds. This feature was used to contrast the monocots with the dicotyledons or dicots which have two cotyledons. From a diagnostic point of view the number of cotyledons is neither a useful characteristic, nor is it reliable; the single cotyledon is only one of a number of modifications of the body plan of the ancestral monocotyledons, whose adaptive advantages are poorly understood, but may have been related to adaption to aquatic habitats, prior to radiation to terrestrial habitats. Monocots are sufficiently distinctive that there has been disagreement as to membership of this group, despite considerable diversity in terms of external morphology.
However, morphological features that reliably characterise major clades are rare. Thus monocots are distinguishable from other angiosperms both in terms of their uniformity and diversity. On the one hand the organisation of the shoots, leaf structure and floral configuration are more uniform than in the remaining angiosperms, yet within these constraints a wealth of diversity exists, indicating a high degree of evolutionary success. Monocot diversity includes perennial geophytes such as ornamental flowers including and succulent epiphytes, all in the lilioid monocots, major cereal grains in the grass family and forage grasses as well as woody tree-like palm trees, bamboo and bromeliads, bananas and ginger in the commelinid monocots, as well as both emergent and aroids, as well as floating or submerged aquatic plants such as seagrass. Organisation and life formsThe most important distinction is their growth pattern, lacking a lateral meristem that allows for continual growth in diameter with height, therefore this characteristic is a basic limitation in shoot construction.
Although herbaceous, some arboraceous monocots reach great height and mass. The latter include agaves, palms and bamboos; this creates challenges in water transport. Some, such as species of Yucca, develop anomalous secondary growth, while palm trees utilise an anomalous primary growth form described as establishment growth; the axis undergoes primary thickening, that progresses from internode to internode, resulting in a typical inverted conical shape of the basal primary axis. The limited conductivity contributes to limited branching of the stems. Despite these limitations a wide variety of adaptive growth forms has resulted from epiphytic orchids and bromeliads to submarine Alismatales and mycotrophic Burmanniaceae and Triuridaceae. Other forms of adaptation include the climbing vines of Araceae which use negative phototropism to locate host trees, while some palms such as Calamus manan produce the longest shoots in the plant kingdom, up to 185 m long. Other monocots Poales, have adopted a therophyte life form.
LeavesThe cotyledon, the primordial Angiosperm leaf consists of a proximal leaf base or hypophyll and a distal hyperphyll. In monocots the hypophyll tends to be the dominant part in contrast to other angiosperms. From these, considerable diversity arises. Mature monocot leaves are narrow and linear, forming a sheath