title: Kronborg content: 'Elsinore Beer' is named for the castle and shown in the beer label logo in the 1983 comedy Strange Brew, starring Rick Moranis and Dave Thomas. in 2017 Hamletscenen presented a production of William Shakespeare's Hamlet at Kronborg castle, directed by Lars Romann Engel. The role of Hamlet was played by Cyron Melville and Ophelia by Natalie Madueño. Music for the production was composed by Mike Sheridan. Kulturhavn Kronborg is an initiative of 2013 to offer a variety of culture experiences to residents and visitors to Helsingør. Kulturhavn Kronborg is a joint initiative by Kronborg Castle, Danish Maritime Museum, Kulturværftet


title: Kronborg content: and Helsingør harbour. Kronborg Kronborg is a castle and stronghold in the town of Helsingør, Denmark. Immortalized as Elsinore in William Shakespeare's play "Hamlet", Kronborg is one of the most important Renaissance castles in Northern Europe and has been added to UNESCO's World Heritage Sites list (2000). The castle is situated on the extreme northeastern tip of the island of Zealand at the narrowest point of the Øresund, the sound between present Denmark and the provinces of present Sweden that were also Danish at the time the castle was built. In this part, the sound is only wide, hence the


title: Banana content: Banana A banana is an edible fruit – botanically a berry – produced by several kinds of large herbaceous flowering plants in the genus "Musa". In some countries, bananas used for cooking may be called "plantains", distinguishing them from dessert bananas. The fruit is variable in size, color, and firmness, but is usually elongated and curved, with soft flesh rich in starch covered with a rind, which may be green, yellow, red, purple, or brown when ripe. The fruits grow in clusters hanging from the top of the plant. Almost all modern edible seedless (parthenocarp) bananas come from two wild


title: Banana content: species – "Musa acuminata" and "Musa balbisiana". The scientific names of most cultivated bananas are "Musa acuminata", "Musa balbisiana", and "Musa" × "paradisiaca" for the hybrid "Musa acuminata" × "M. balbisiana", depending on their genomic constitution. The old scientific name "Musa sapientum" is no longer used. "Musa" species are native to tropical Indomalaya and Australia, and are likely to have been first domesticated in Papua New Guinea. They are grown in 135 countries, primarily for their fruit, and to a lesser extent to make fiber, banana wine, and banana beer and as ornamental plants. The world's largest producers of bananas


title: Banana content: in 2016 were India and China, which together accounted for 28% of total production. Worldwide, there is no sharp distinction between "bananas" and "plantains". Especially in the Americas and Europe, "banana" usually refers to soft, sweet, dessert bananas, particularly those of the Cavendish group, which are the main exports from banana-growing countries. By contrast, "Musa" cultivars with firmer, starchier fruit are called "plantains". In other regions, such as Southeast Asia, many more kinds of banana are grown and eaten, so the binary distinction is not useful and is not made in local languages. The term "banana" is also used as


title: Banana content: the common name for the plants that produce the fruit. This can extend to other members of the genus "Musa", such as the scarlet banana ("Musa coccinea"), the pink banana ("Musa velutina"), and the Fe'i bananas. It can also refer to members of the genus "Ensete", such as the snow banana ("Ensete glaucum") and the economically important false banana ("Ensete ventricosum"). Both genera are in the banana family, Musaceae. The banana plant is the largest herbaceous flowering plant. All the above-ground parts of a banana plant grow from a structure usually called a "corm". Plants are normally tall and fairly


title: Banana content: sturdy, and are often mistaken for trees, but what appears to be a trunk is actually a "false stem" or pseudostem. Bananas grow in a wide variety of soils, as long as the soil is at least 60 cm deep, has good drainage and is not compacted. The leaves of banana plants are composed of a "stalk" (petiole) and a blade (lamina). The base of the petiole widens to form a sheath; the tightly packed sheaths make up the pseudostem, which is all that supports the plant. The edges of the sheath meet when it is first produced, making it


title: Banana content: tubular. As new growth occurs in the centre of the pseudostem the edges are forced apart. Cultivated banana plants vary in height depending on the variety and growing conditions. Most are around tall, with a range from 'Dwarf Cavendish' plants at around to 'Gros Michel' at or more. Leaves are spirally arranged and may grow long and wide. They are easily torn by the wind, resulting in the familiar frond look. When a banana plant is mature, the corm stops producing new leaves and begins to form a flower spike or inflorescence. A stem develops which grows up inside the


title: Banana content: pseudostem, carrying the immature inflorescence until eventually it emerges at the top. Each pseudostem normally produces a single inflorescence, also known as the "banana heart". (More are sometimes produced; an exceptional plant in the Philippines produced five.) After fruiting, the pseudostem dies, but offshoots will normally have developed from the base, so that the plant as a whole is perennial. In the plantation system of cultivation, only one of the offshoots will be allowed to develop in order to maintain spacing. The inflorescence contains many bracts (sometimes incorrectly referred to as petals) between rows of flowers. The female flowers (which


title: Banana content: can develop into fruit) appear in rows further up the stem (closer to the leaves) from the rows of male flowers. The ovary is inferior, meaning that the tiny petals and other flower parts appear at the tip of the ovary. The banana fruits develop from the banana heart, in a large hanging cluster, made up of tiers (called "hands"), with up to 20 fruit to a tier. The hanging cluster is known as a bunch, comprising 3–20 tiers, or commercially as a "banana stem", and can weigh . Individual banana fruits (commonly known as a banana or "finger") average


title: Banana content: , of which approximately 75% is water and 25% dry matter (nutrient table, lower right). The fruit has been described as a "leathery berry". There is a protective outer layer (a peel or skin) with numerous long, thin strings (the phloem bundles), which run lengthwise between the skin and the edible inner portion. The inner part of the common yellow dessert variety can be split lengthwise into three sections that correspond to the inner portions of the three carpels by manually deforming the unopened fruit. In cultivated varieties, the seeds are diminished nearly to non-existence; their remnants are tiny black


title: Banana content: specks in the interior of the fruit. Bananas are naturally slightly radioactive, more so than most other fruits, because of their potassium content and the small amounts of the isotope potassium-40 found in naturally occurring potassium. The banana equivalent dose of radiation is sometimes used in nuclear communication to compare radiation levels and exposures. The word banana is thought to be of West African origin, possibly from the Wolof word "banaana", and passed into English via Spanish or Portuguese. The genus "Musa" was created by Carl Linnaeus in 1753. The name may be derived from Antonius Musa, physician to the


title: Banana content: Emperor Augustus, or Linnaeus may have adapted the Arabic word for banana, "mauz". The old biological name "Musa sapientum" = "Muse of the wise" arose because of homophony in Latin with the classical Muses. "Musa" is in the family Musaceae. The APG III system assigns Musaceae to the order Zingiberales, part of the commelinid clade of the monocotyledonous flowering plants. Some 70 species of "Musa" were recognized by the World Checklist of Selected Plant Families ; several produce edible fruit, while others are cultivated as ornamentals. The classification of cultivated bananas has long been a problematic issue for taxonomists. Linnaeus


title: Banana content: originally placed bananas into two species based only on their uses as food: "Musa sapientum" for dessert bananas and "Musa paradisiaca" for plantains. More species names were added, but this approach proved to be inadequate for the number of cultivars in the primary center of diversity of the genus, Southeast Asia. Many of these cultivars were given names that were later discovered to be synonyms. In a series of papers published from 1947 onwards, Ernest Cheesman showed that Linnaeus's "Musa sapientum" and "Musa paradisiaca" were cultivars and descendants of two wild seed-producing species, "Musa acuminata" and "Musa balbisiana", both first


title: Banana content: described by Luigi Aloysius Colla. Cheesman recommended the abolition of Linnaeus's species in favor of reclassifying bananas according to three morphologically distinct groups of cultivars – those primarily exhibiting the botanical characteristics of "Musa balbisiana", those primarily exhibiting the botanical characteristics of "Musa acuminata", and those with characteristics of both. Researchers Norman Simmonds and Ken Shepherd proposed a genome-based nomenclature system in 1955. This system eliminated almost all the difficulties and inconsistencies of the earlier classification of bananas based on assigning scientific names to cultivated varieties. Despite this, the original names are still recognized by some authorities today, leading to


title: Banana content: confusion. The accepted scientific names for most groups of cultivated bananas are Musa acuminata and Musa balbisiana for the ancestral species, and Musa" × "paradisiaca for the hybrid "M. acuminata" × "M. balbisiana". Synonyms of "M." × "paradisica" include Generally, modern classifications of banana cultivars follow Simmonds and Shepherd's system. Cultivars are placed in groups based on the number of chromosomes they have and which species they are derived from. Thus the Latundan banana is placed in the AAB Group, showing that it is a triploid derived from both "M. acuminata" (A) and "M. balbisiana" (B). For a list of


title: Banana content: the cultivars classified under this system, "see" "List of banana cultivars". In 2012, a team of scientists announced they had achieved a draft sequence of the genome of "Musa acuminata". In regions such as North America and Europe, "Musa" fruits offered for sale can be divided into "bananas" and "plantains", based on their intended use as food. Thus the banana producer and distributor Chiquita produces publicity material for the American market which says that "a plantain is not a banana". The stated differences are that plantains are more starchy and less sweet; they are eaten cooked rather than raw; they


title: Banana content: have thicker skin, which may be green, yellow or black; and they can be used at any stage of ripeness. Linnaeus made the same distinction between plantains and bananas when first naming two "species" of "Musa". Members of the "plantain subgroup" of banana cultivars, most important as food in West Africa and Latin America, correspond to the Chiquita description, having long pointed fruit. They are described by Ploetz et al. as "true" plantains, distinct from other cooking bananas. The cooking bananas of East Africa belong to a different group, the East African Highland bananas, so would not qualify as "true"


title: Banana content: plantains on this definition. An alternative approach divides bananas into dessert bananas and cooking bananas, with plantains being one of the subgroups of cooking bananas. Triploid cultivars derived solely from "M. acuminata" are examples of "dessert bananas", whereas triploid cultivars derived from the hybrid between "M. acuminata" and "M. balbinosa" (in particular the plantain subgroup of the AAB Group) are "plantains". Small farmers in Colombia grow a much wider range of cultivars than large commercial plantations. A study of these cultivars showed that they could be placed into at least three groups based on their characteristics: dessert bananas, non-plantain cooking


title: Banana content: bananas, and plantains, although there were overlaps between dessert and cooking bananas. In Southeast Asia – the center of diversity for bananas, both wild and cultivated – the distinction between "bananas" and "plantains" does not work, according to Valmayor et al. Many bananas are used both raw and cooked. There are starchy cooking bananas which are smaller than those eaten raw. The range of colors, sizes and shapes is far wider than in those grown or sold in Africa, Europe or the Americas. Southeast Asian languages do not make the distinction between "bananas" and "plantains" that is made in English


title: Banana content: (and Spanish). Thus both Cavendish cultivars, the classic yellow dessert bananas, and Saba cultivars, used mainly for cooking, are called "pisang" in Malaysia and Indonesia, "kluai" in Thailand and "chuoi" in Vietnam. Fe'i bananas, grown and eaten in the islands of the Pacific, are derived from entirely different wild species than traditional bananas and plantains. Most Fe'i bananas are cooked, but Karat bananas, which are short and squat with bright red skins, very different from the usual yellow dessert bananas, are eaten raw. In summary, in commerce in Europe and the Americas (although not in small-scale cultivation), it is possible


title: Banana content: to distinguish between "bananas", which are eaten raw, and "plantains", which are cooked. In other regions of the world, particularly India, Southeast Asia and the islands of the Pacific, there are many more kinds of banana and the two-fold distinction is not useful and not made in local languages. Plantains are one of many kinds of cooking bananas, which are not always distinct from dessert bananas. Farmers in Southeast Asia and Papua New Guinea first domesticated bananas. Recent archaeological and palaeoenvironmental evidence at Kuk Swamp in the Western Highlands Province of Papua New Guinea suggests that banana cultivation there goes


title: Banana content: back to at least 5000 BCE, and possibly to 8000 BCE. It is likely that other species were later and independently domesticated elsewhere in Southeast Asia. Southeast Asia is the region of primary diversity of the banana. Areas of secondary diversity are found in Africa, indicating a long history of banana cultivation in the region. Phytolith discoveries in Cameroon dating to the first millennium BCE triggered an as yet unresolved debate about the date of first cultivation in Africa. There is linguistic evidence that bananas were known in Madagascar around that time. The earliest prior evidence indicates that cultivation dates


title: Banana content: to no earlier than late 6th century CE. It is likely, however, that bananas were brought at least to Madagascar if not to the East African coast during the phase of Malagasy colonization of the island from South East Asia c. 400 CE. The banana may also have been present in isolated locations elsewhere in the Middle East on the eve of Islam. The spread of Islam was followed by far-reaching diffusion. There are numerous references to it in Islamic texts (such as poems and hadiths) beginning in the 9th century. By the 10th century the banana appears in texts


title: Banana content: from Palestine and Egypt. From there it diffused into North Africa and Muslim Iberia. During the medieval ages, bananas from Granada were considered among the best in the Arab world. In 650, Islamic conquerors brought the banana to Palestine. Today, banana consumption increases significantly in Islamic countries during Ramadan, the month of daylight fasting. Bananas were certainly grown in the Christian Kingdom of Cyprus by the late medieval period. Writing in 1458, the Italian traveller and writer wrote favourably of the extensive farm produce of the estates at Episkopi, near modern-day Limassol, including the region's banana plantations. Bananas were introduced


title: Banana content: to the Americas by Portuguese sailors who brought the fruits from West Africa in the 16th century. Many wild banana species as well as cultivars exist in extraordinary diversity in India, China, and Southeast Asia. In the 15th and 16th centuries, Portuguese colonists started banana plantations in the Atlantic Islands, Brazil, and western Africa. North Americans began consuming bananas on a small scale at very high prices shortly after the Civil War, though it was only in the 1880s that the food became more widespread. As late as the Victorian Era, bananas were not widely known in Europe, although they


title: Banana content: were available. Jules Verne introduces bananas to his readers with detailed descriptions in "Around the World in Eighty Days" (1872). The earliest modern plantations originated in Jamaica and the related Western Caribbean Zone, including most of Central America. It involved the combination of modern transportation networks of steamships and railroads with the development of refrigeration that allowed more time between harvesting and ripening. North American shippers like Lorenzo Dow Baker and Andrew Preston, the founders of the Boston Fruit Company started this process in the 1870s, but railroad builders like Minor C. Keith also participated, eventually culminating in the multi-national


title: Banana content: giant corporations like today's Chiquita Brands International and Dole. These companies were monopolistic, vertically integrated (meaning they controlled growing, processing, shipping and marketing) and usually used political manipulation to build enclave economies (economies that were internally self-sufficient, virtually tax exempt, and export-oriented that contribute very little to the host economy). Their political maneuvers, which gave rise to the term Banana republic for states like Honduras and Guatemala, included working with local elites and their rivalries to influence politics or playing the international interests of the United States, especially during the Cold War, to keep the political climate favorable to their


title: Banana content: interests. The vast majority of the world's bananas today are cultivated for family consumption or for sale on local markets. India is the world leader in this sort of production, but many other Asian and African countries where climate and soil conditions allow cultivation also host large populations of banana growers who sell at least some of their crop. Peasant sector banana growers produce for the world market in the Caribbean, however. The Windward Islands are notable for the growing, largely of Cavendish bananas, for an international market, generally in Europe but also in North America. In the Caribbean, and


title: Banana content: especially in Dominica where this sort of cultivation is widespread, holdings are in the 1–2 acre range. In many cases the farmer earns additional money from other crops, from engaging in labor outside the farm, and from a share of the earnings of relatives living overseas. Banana crops are vulnerable to destruction by high winds, such as tropical storms or cyclones. All widely cultivated bananas today descend from the two wild bananas "Musa acuminata" and "Musa balbisiana". While the original wild bananas contained large seeds, diploid or polyploid cultivars (some being hybrids) with tiny seeds are preferred for human raw


title: Banana content: fruit consumption. These are propagated asexually from offshoots. The plant is allowed to produce two shoots at a time; a larger one for immediate fruiting and a smaller "sucker" or "follower" to produce fruit in 6–8 months. As a non-seasonal crop, bananas are available fresh year-round. In global commerce in 2009, by far the most important cultivars belonged to the triploid AAA group of "Musa acuminata", commonly referred to as Cavendish group bananas. They accounted for the majority of banana exports, despite only coming into existence in 1836. The cultivars Dwarf Cavendish and Grand Nain (Chiquita Banana) gained popularity in


title: Banana content: the 1950s after the previous mass-produced cultivar, Gros Michel (also an AAA group cultivar), became commercially unviable due to Panama disease, caused by the fungus "Fusarium oxysporum" which attacks the roots of the banana plant. Cavendish cultivars are resistant to the Panama disease, but in 2013 there were fears that the black sigatoka fungus would in turn make Cavendish bananas unviable. Even though it is no longer viable for large scale cultivation, Gros Michel is not extinct and is still grown in areas where Panama disease is not found. Likewise, Dwarf Cavendish and Grand Nain are in no danger of


title: Banana content: extinction, but they may leave supermarket shelves if disease makes it impossible to supply the global market. It is unclear if any existing cultivar can replace Cavendish bananas, so various hybridisation and genetic engineering programs are attempting to create a disease-resistant, mass-market banana. One such strain that has emerged is the Taiwanese Cavendish, also known as the Formosana. Export bananas are picked green, and ripen in special rooms upon arrival in the destination country. These rooms are air-tight and filled with ethylene gas to induce ripening. The vivid yellow color consumers normally associate with supermarket bananas is, in fact, caused


title: Banana content: by the artificial ripening process. Flavor and texture are also affected by ripening temperature. Bananas are refrigerated to between during transport. At lower temperatures, ripening permanently stalls, and the bananas turn gray as cell walls break down. The skin of ripe bananas quickly blackens in the environment of a domestic refrigerator, although the fruit inside remains unaffected. Bananas can be ordered by the retailer "ungassed" ("i.e." not treated with ethylene), and may show up at the supermarket fully green. (green bananas) that have not been gassed will never fully ripen before becoming rotten. Instead of fresh eating, these bananas can


title: Banana content: be used for cooking, as seen in Jamaican cuisine. A 2008 study reported that ripe bananas fluoresce when exposed to ultraviolet light. This property is attributed to the degradation of chlorophyll leading to the accumulation of a fluorescent product in the skin of the fruit. The chlorophyll breakdown product is stabilized by a propionate ester group. Banana-plant leaves also fluoresce in the same way. Green bananas do not fluoresce. The study suggested that this allows animals which can see light in the ultraviolet spectrum (tetrachromats and pentachromats) to more easily detect ripened bananas. Bananas must be transported over long distances


title: Banana content: from the tropics to world markets. To obtain maximum shelf life, harvest comes before the fruit is mature. The fruit requires careful handling, rapid transport to ports, cooling, and refrigerated shipping. The goal is to prevent the bananas from producing their natural ripening agent, ethylene. This technology allows storage and transport for 3–4 weeks at . On arrival, bananas are held at about and treated with a low concentration of ethylene. After a few days, the fruit begins to ripen and is distributed for final sale. Ripe bananas can be held for a few days at home. If bananas are


title: Banana content: too green, they can be put in a brown paper bag with an apple or tomato overnight to speed up the ripening process. Carbon dioxide (which bananas produce) and ethylene absorbents extend fruit life even at high temperatures. This effect can be exploited by packing banana in a polyethylene bag and including an ethylene absorbent, e.g., potassium permanganate, on an inert carrier. The bag is then sealed with a band or string. This treatment has been shown to more than double lifespans up to 3–4 weeks without the need for refrigeration. In 2016, world production of bananas and plantains was


title: Banana content: 148 million tonnes, led by India and China with a combined total (only for bananas) of 28% of global production (table). Other major producers were the Philippines, Ecuador, Indonesia, and Brazil, together accounting for 20% of the world total of bananas and plantains (table). As reported for 2013, total world exports were 20 million tonnes of bananas and 859,000 tonnes of plantains. Ecuador and the Philippines were the leading exporters with 5.4 and 3.3 million tonnes, respectively, and the Dominican Republic was the leading exporter of plantains with 210,350 tonnes. Bananas and plantains constitute a major staple food crop for


title: Banana content: millions of people in developing countries. In most tropical countries, green (unripe) bananas used for cooking represent the main cultivars. Most producers are small-scale farmers either for home consumption or local markets. Because bananas and plantains produce fruit year-round, they provide a valuable food source during the "hunger season" (when the food from one annual/semi-annual harvest has been consumed, and the next is still to come). Bananas and plantains are important for global food security. While in no danger of outright extinction, the most common edible banana cultivar Cavendish (extremely popular in Europe and the Americas) could become unviable for


title: Banana content: large-scale cultivation in the next 10–20 years. Its predecessor 'Gros Michel', discovered in the 1820s, suffered this fate. Like almost all bananas, Cavendish lacks genetic diversity, which makes it vulnerable to diseases, threatening both commercial cultivation and small-scale subsistence farming. Some commentators remarked that those variants which could replace what much of the world considers a "typical banana" are so different that most people would not consider them the same fruit, and blame the decline of the banana on monogenetic cultivation driven by short-term commercial motives. Panama disease is caused by a fusarium soil fungus (Race 1), which enters the


title: Banana content: plants through the roots and travels with water into the trunk and leaves, producing gels and gums that cut off the flow of water and nutrients, causing the plant to wilt, and exposing the rest of the plant to lethal amounts of sunlight. Prior to 1960, almost all commercial banana production centered on "Gros Michel", which was highly susceptible. Cavendish was chosen as the replacement for Gros Michel because, among resistant cultivars, it produces the highest quality fruit. However, more care is required for shipping the Cavendish, and its quality compared to Gros Michel is debated. According to current sources,


title: Banana content: a deadly form of Panama disease is infecting Cavendish. All plants are genetically identical, which prevents evolution of disease resistance. Researchers are examining hundreds of wild varieties for resistance. Tropical race 4 (TR4), a reinvigorated strain of Panama disease, was first discovered in 1993. This virulent form of fusarium wilt has wiped out Cavendish in several southeast Asian countries and has recently spread to Australia, India and Mozambique. It has yet to reach the Americas; however, the soil-based fungi can easily be carried on boots, clothing, or tools. This is how TR4 travels and will be its most likely route


title: Banana content: into Latin America. Cavendish is highly susceptible to TR4, and over time Cavendish will almost certainly be eliminated from commercial production by this disease. The only known defense to TR4 is genetic resistance. This is conferred either by RGA2, a gene isolated from a TR4-resistant diploid banana, or by the nematode-derived Ced9. Black sigatoka is a fungal leaf spot disease first observed in Fiji in 1963 or 1964. Black Sigatoka (also known as black leaf streak) has spread to banana plantations throughout the tropics from infected banana leaves that were used as packing material. It affects all main cultivars of


title: Banana content: bananas and plantains (including the Cavendish cultivars), impeding photosynthesis by blackening parts of the leaves, eventually killing the entire leaf. Starved for energy, fruit production falls by 50% or more, and the bananas that do grow ripen prematurely, making them unsuitable for export. The fungus has shown ever-increasing resistance to treatment, with the current expense for treating exceeding $1,000 per year. In addition to the expense, there is the question of how long intensive spraying can be environmentally justified. Banana bunchy top virus (BBTV) is a plant virus of the genus "Babuvirus", family "Nanonviridae" affecting "Musa spp." (including banana, abaca,


title: Banana content: plantain and ornamental bananas) and "Ensete spp." in the family "Musaceae". Banana Bunchy Top Disease (BBTD) symptoms include dark green streaks of variable length in leaf veins, midribs and petioles. Leaves become short and stunted as the disease progresses, becoming 'bunched' at the apex of the plant. Infected plants may produce no fruit or the bunch may not emerge from the pseudostem. Banana bacterial wilt (BBW) is a bacterial disease caused by "Xanthomonas campestris" pv. "musacearum". After being originally identified on a close relative of bananas, "Ensete ventricosum", in Ethiopia in the 1960s, BBW occurred in Uganda in 2001 affecting


title: Banana content: all banana cultivars. Since then BBW has been diagnosed in Central and East Africa including the banana growing regions of Rwanda, the Democratic Republic of the Congo, Tanzania, Kenya, Burundi, and Uganda. Given the narrow range of genetic diversity present in bananas and the many threats via biotic (pests and diseases) and abiotic (such as drought) stress, conservation of the full spectrum of banana genetic resources is ongoing. Banana germplasm is conserved in many national and regional gene banks, and at the world's largest banana collection, the International "Musa" Germplasm Transit Centre (ITC), managed by Bioversity International and hosted at


title: Banana content: KU Leuven in Belgium. "Musa" cultivars are usually seedless, and options for their long-term conservation are constrained by the vegetative nature of the plant's reproductive system. Consequently, they are conserved by three main methods: "in vivo" (planted in field collections), "in vitro" (as plantlets in test tubes within a controlled environment), and by cryopreservation (meristems conserved in liquid nitrogen at -196 °C). Genes from wild banana species are conserved as DNA and as cryopreserved pollen and banana seeds from wild species are also conserved, although less commonly, as they are difficult to regenerate. In addition, bananas and their crop wild


title: Banana content: relatives are conserved "in situ" (in wild natural habitats where they evolved and continue to do so). Diversity is also conserved in farmers' fields where continuous cultivation, adaptation and improvement of cultivars is often carried out by small-scale farmers growing traditional local cultivars (including home gardens). Raw bananas (not including the peel) are 75% water, 23% carbohydrates, 1% protein, and contain negligible fat. A 100-gram serving supplies 89 Calories, 31% of the US recommended Daily Value of vitamin B, and moderate amounts of vitamin C, manganese and dietary fiber (see table). Bananas are a staple starch for many tropical populations.


title: Banana content: Depending upon cultivar and ripeness, the flesh can vary in taste from starchy to sweet, and texture from firm to mushy. Both the skin and inner part can be eaten raw or cooked. The primary component of the aroma of fresh bananas is isoamyl acetate (also known as "banana oil"), which, along with several other compounds such as butyl acetate and isobutyl acetate, is a significant contributor to banana flavor. During the ripening process, bananas produce the gas ethylene, which acts as a plant hormone and indirectly affects the flavor. Among other things, ethylene stimulates the formation of amylase, an


title: Banana content: enzyme that breaks down starch into sugar, influencing the taste of bananas. The greener, less ripe bananas contain higher levels of starch and, consequently, have a "starchier" taste. On the other hand, yellow bananas taste sweeter due to higher sugar concentrations. Furthermore, ethylene signals the production of pectinase, an enzyme which breaks down the pectin between the cells of the banana, causing the banana to soften as it ripens. Bananas are eaten deep fried, baked in their skin in a split bamboo, or steamed in glutinous rice wrapped in a banana leaf. Bananas can be made into jam. Banana pancakes


title: Banana content: are popular amongst backpackers and other travelers in South Asia and Southeast Asia. This has elicited the expression "Banana Pancake Trail" for those places in Asia that cater to this group of travelers. Banana chips are a snack produced from sliced dehydrated or fried banana or plantain, which have a dark brown color and an intense banana taste. Dried bananas are also ground to make banana flour. Extracting juice is difficult, because when a banana is compressed, it simply turns to pulp. Bananas feature prominently in Philippine cuisine, being part of traditional dishes and desserts like "maruya", "turón", and "halo-halo"


title: Banana content: or "saba con yelo". Most of these dishes use the Saba or Cardaba banana cultivar. Bananas are also commonly used in cuisine in the South-Indian state of Kerala, where they are steamed ("puzhungiyathu"), made into curries, fried into chips, ("upperi") or fried in batter ("pazhampori"). Pisang goreng, bananas fried with batter similar to the Filipino "maruya" or Kerala "pazhampori", is a popular dessert in Malaysia, Singapore, and Indonesia. A similar dish is known in the United Kingdom and United States as banana fritters. Plantains are used in various stews and curries or cooked, baked or mashed in much the same


title: Banana content: way as potatoes, such as the pazham pachadi dish prepared in Kerala. Banana hearts are used as a vegetable in South Asian and Southeast Asian cuisine, either raw or steamed with dips or cooked in soups, curries and fried foods. The flavor resembles that of artichoke. As with artichokes, both the fleshy part of the bracts and the heart are edible. Banana leaves are large, flexible, and waterproof. They are often used as ecologically friendly disposable food containers or as "plates" in South Asia and several Southeast Asian countries. In Indonesian cuisine, banana leaf is employed in cooking methods like


title: Banana content: pepes and botok; banana leaf packages containing food ingredients and spices are cooked in steam or in boiled water, or are grilled on charcoal. When used so for steaming or grilling, the banana leaves protect the food ingredients from burning and add a subtle sweet flavor. In South India, it is customary to serve traditional food on a banana leaf. In Tamil Nadu (India), dried banana leaves are used as to pack food and to make cups to hold liquid food items. The tender core of the banana plant's trunk is also used in South Asian and Southeast Asian cuisine,


title: Banana content: and notably in the Burmese dish mohinga. Banana fiber harvested from the pseudostems and leaves of the plant has been used for textiles in Asia since at least the 13th century. Both fruit-bearing and fibrous varieties of the banana plant have been used. In the Japanese system Kijōka-bashōfu, leaves and shoots are cut from the plant periodically to ensure softness. Harvested shoots are first boiled in lye to prepare fibers for yarn-making. These banana shoots produce fibers of varying degrees of softness, yielding yarns and textiles with differing qualities for specific uses. For example, the outermost fibers of the shoots


title: Banana content: are the coarsest, and are suitable for tablecloths, while the softest innermost fibers are desirable for kimono and kamishimo. This traditional Japanese cloth-making process requires many steps, all performed by hand. In India, a banana fiber separator machine has been developed, which takes the agricultural waste of local banana harvests and extracts strands of the fiber. Banana fiber is used in the production of banana paper. Banana paper is made from two different parts: the bark of the banana plant, mainly used for artistic purposes, or from the fibers of the stem and non-usable fruits. The paper is either hand-made


title: Banana content: or by industrial process. In all the important festivals and occasions of Hindus, the serving of bananas plays a prominent part. In Thailand, it is believed that a certain type of banana plants may be inhabited by a spirit, Nang Tani, a type of ghost related to trees and similar plants that manifests itself as a young woman. Often people tie a length of colored satin cloth around the pseudostem of the banana plants. In Malay folklore, the ghost known as Pontianak is associated with banana plants ("pokok pisang"), and its spirit is said to reside in them during the


title: Banana content: day. There is a long racist history of describing people of African descent as being more like monkeys than humans, and due to the assumption in popular culture that monkeys like bananas, bananas have been used in symbolic acts of hate speech. In April 2014, during a match at Villarreal's stadium, El Madrigal, Dani Alves was targeted by Villareal supporter David Campaya Lleo, who threw a banana at him. Alves picked up the banana, peeled it and took a bite, and the meme went viral on social media in support of him. Racist taunts are an ongoing problem in football.


title: Banana content: Bananas were hung from nooses around the campus of American University in May 2017 after the student body elected its first black woman student government president. The Unicode standard includes the emoji character . Banana A banana is an edible fruit – botanically a berry – produced by several kinds of large herbaceous flowering plants in the genus "Musa". In some countries, bananas used for cooking may be called "plantains", distinguishing them from dessert bananas. The fruit is variable in size, color, and firmness, but is usually elongated and curved, with soft flesh rich in starch covered with a rind,


title: Goldie content: To Life", Roy Ayers' "Everybody Loves The Sunshine") with cuts that soundtracked his entry into the rave scene and key moments from the drum'n'bass scene. Price has appeared in Guy Ritchie's "Snatch" and several other films, most notably the James Bond film, "The World Is Not Enough". He also played gangster Angel Hudson in the British soap opera "EastEnders" (2001–2002). Price starred in "Everybody Loves Sunshine" (1999) (aka "B.U.S.T.E.D." – United States title) with David Bowie. In the late 1980s, Price appeared on "Central Weekend", a Friday evening topical debate show on Central TV, promoting graffiti as an art form.


title: Vulcanization content: Vulcanization Vulcanization (British: vulcanisation) is a chemical process used to harden rubber. Vulcanization traditionally referred to the treatment of natural rubber with sulfur and this remains the most common example, however the term has also grown to include the hardening of other (synthetic) rubbers via various means. Examples include silicone rubber via room temperature vulcanizing and chloroprene rubber (neoprene) using metal oxides. Vulcanisation can therefore be defined as the curing of elastomers; with the terms 'vulcanization' and 'curing' sometimes used interchangeably in this context. It works by forming cross-links between sections of polymer chain which results in increased rigidity and


title: "Robbie Williams" content: 1 on the German Albums Chart for 38 weeks since 2000. He also reached that chart's Top Ten 135 times. Since 2006, Williams has spent most of his time in Los Angeles. He briefly moved back to the UK in 2009 when he bought an £8.5 million mansion in Compton Bassett, Wiltshire, nearby to close friend Jonathan Wilkes who lives in Swindon, but sold the property a year later to move back to Los Angeles. In 2017 he sold his mansion in Beverly Hills for $9.9 million to DJ Khaled. In 2016 he moved into a £17 million mansion in


title: "Lawrence Livermore National Laboratory" content: lab persevered and its subsequent designs proved increasingly successful. In 1957, the Livermore Lab was selected to develop the warhead for the Navy's Polaris missile. This warhead required numerous innovations to fit a nuclear warhead into the relatively small confines of the missile nosecone. During the Cold War, many Livermore-designed warheads entered service. These were used in missiles ranging in size from the Lance surface-to-surface tactical missile to the megaton-class Spartan antiballistic missile. Over the years, LLNL designed the following warheads: W27 (Regulus cruise missile; 1955; joint with Los Alamos), W38 (Atlas/Titan ICBM; 1959), B41 (B52 bomb; 1957), W45 (Little


title: "African clawed frog" content: African clawed frog The African clawed frog ("Xenopus laevis", also known as the xenopus, African clawed toad, African claw-toed frog or the platanna) is a species of African aquatic frog of the family Pipidae. Its name is derived from the three short claws on each hind foot, which it uses to tear apart its food. The word "Xenopus" means "strange foot" and "laevis" means "smooth". The species is found throughout much of Sub-Saharan Africa (Nigeria and Sudan to South Africa), and in isolated, introduced populations in North America, South America, and Europe. All species of the family Pipidae are tongueless,


title: "African clawed frog" content: toothless and completely aquatic. They use their hands to shove food in their mouths and down their throats and a hyobranchial pump to draw or suck things in their mouth. Pipidae have powerful legs for swimming and lunging after food. They also use the claws on their feet to tear pieces of large food. They lack true ears, but have lateral lines running down the length of the body and underside, which is how they can sense movements and vibrations in the water. They use their sensitive fingers, sense of smell, and lateral line system to find food. Pipidae are


title: "African clawed frog" content: scavengers and will eat almost anything living, dying, or dead and any type of organic waste. These frogs are plentiful in ponds and rivers within the south-eastern portion of Sub-Saharan Africa. They are aquatic and are often greenish-grey in color. Albino varieties are commonly sold as pets. "Wild type" African clawed frogs are also frequently sold as pets, and often incorrectly labeled as a Congo frog or African dwarf frog because of similar colorings. They are easily distinguished from African dwarf frogs because African clawed frogs have webbing only on their hind feet while African dwarf frogs have webbing on


title: "African clawed frog" content: all four feet. They reproduce by fertilizing eggs outside of the female's body (see frog reproduction). Of the seven amplexus modes (positions in which frogs mate), these frogs are found breeding in inguinal amplexus, where the male clasps the female in front of the female's back legs and squeezes until eggs come out. The eggs are then fertilized. The clawed frogs are the only amphibians to have actual claws used to climb and shred foods like fish or tadpoles. They lay their eggs from winter until spring. During wet rainy seasons they will travel to other ponds or puddles of


title: "African clawed frog" content: water to search for food. "X. laevis" have been known to survive 15 or more years in the wild and 25–30 years in captivity. They shed their skin every season, and eat their own shed skin. Although lacking a vocal sac, the males make a mating call of alternating long and short trills, by contracting the intrinsic laryngeal muscles. Females also answer vocally, signaling either acceptance (a rapping sound) or rejection (slow ticking) of the male. This frog has smooth slippery skin which is multicolored on its back with blotches of olive gray or brown. The underside is creamy white


title: "African clawed frog" content: with a yellow tinge. Male and female frogs can be easily distinguished through the following differences. Male frogs are usually about 20% smaller than females, with slim bodies and legs. Males make mating calls to attract females, sounding very much like a cricket calling underwater. Females are larger than the males, appearing far more plump with hip-like bulges above their rear legs (where their eggs are internally located). Both males and females have a cloaca, which is a chamber through which digestive and urinary wastes pass and through which the reproductive systems also empty. The cloaca empties by way of


title: "African clawed frog" content: the vent which in reptiles and amphibians is a single opening for all three systems. In the wild, "Xenopus laevis" are native to wetlands, ponds, and lakes across arid/semiarid regions of Sub-Saharan Africa. "Xenopus laevis" and "Xenopus muelleri" occur along the western boundary of the Great African Rift. The people of the sub-Saharan are generally very familiar with this frog, and some cultures use it as a source of protein, an aphrodisiac, or as fertility medicine. Two historic outbreaks of priapism have been linked to consumption of frog legs from frogs that ate insects containing cantharidin. Wild "Xenopus" are much


title: "African clawed frog" content: larger than their captive bred counterparts. "Xenopus laevis" in the wild are commonly infected by various parasites, including monogeneans in the urinary bladder. "Xenopus" embryos and eggs are a popular model system for a wide variety of biological studies. This animal is widely used because of its powerful combination of experimental tractability and close evolutionary relationship with humans, at least compared to many model organisms. For a more comprehensive discussion of the use of these frogs in biomedical research, see "Xenopus". In the early 1930s, two South African researchers, Hillel Shapiro and Harry Zwarenstein, who were students of Lancelot Hogben


title: "African clawed frog" content: at Cape Town University, developed a test for human pregnancy by injecting the woman's urine into a Xenopus laevis frog. If the frog ovulated, the woman was pregnant. This simple and reliable test was universally used throughout the 1930s to 1960s. "Xenopus" has long been an important tool for in vivo studies in molecular, cell, and developmental biology of vertebrate animals. However, the wide breadth of "Xenopus" research stems from the additional fact that cell-free extracts made from "Xenopus" are a premier in vitro system for studies of fundamental aspects of cell and molecular biology. Thus, "Xenopus" is the only


title: "African clawed frog" content: vertebrate model system that allows for high-throughput in vivo analyses of gene function and high-throughput biochemistry. Finally, "Xenopus" oocytes are a leading system for studies of ion transport and channel physiology. Although "X. laevis" does not have the short generation time and genetic simplicity generally desired in genetic model organisms, it is an important model organism in developmental biology, cell biology, toxicology and neurobiology. "X. laevis" takes 1 to 2 years to reach sexual maturity and, like most of its genus, it is tetraploid. It does have a large and easily manipulated embryo, however. The ease of manipulation in amphibian


title: "African clawed frog" content: embryos has given them an important place in historical and modern developmental biology. A related species, "Xenopus tropicalis", is now being promoted as a more viable model for genetics. Roger Wolcott Sperry used "X. laevis" for his famous experiments describing the development of the visual system. These experiments led to the formulation of the Chemoaffinity hypothesis. "Xenopus" oocytes provide an important expression system for molecular biology. By injecting DNA or mRNA into the oocyte or developing embryo, scientists can study the protein products in a controlled system. This allows rapid functional expression of manipulated DNAs (or mRNA). This is particularly


title: "African clawed frog" content: useful in electrophysiology, where the ease of recording from the oocyte makes expression of membrane channels attractive. One challenge of oocyte work is eliminating native proteins that might confound results, such as membrane channels native to the oocyte. Translation of proteins can be blocked or splicing of pre-mRNA can be modified by injection of Morpholino antisense oligos into the oocyte (for distribution throughout the embryo) or early embryo (for distribution only into daughter cells of the injected cell). Extracts from the eggs of "X. laevis" frogs are also commonly used for biochemical studies of DNA replication and repair, as these


title: "African clawed frog" content: extracts fully support DNA replication and other related processes in a cell-free environment which allows easier manipulation. The first vertebrate ever to be cloned was an African clawed frog, an experiment for which Sir John Gurdon was awarded the Nobel Prize in Physiology or Medicine 2012 "for the discovery that mature cells can be reprogrammed to become pluripotent". Additionally, several African clawed frogs were present on the Space Shuttle Endeavour (which was launched into space on September 12, 1992) so that scientists could test whether reproduction and development could occur normally in zero gravity. "X. laevis" is also notable for


title: "African clawed frog" content: its use in the first widely used method of pregnancy testing, after Lancelot Hogben discovered that the urine from pregnant women induced "X. laevis" oocyte production. Human chorionic gonadotropin (HCG) is a hormone found in substantial quantities in the urine of pregnant women. Today, commercially available HCG is injected into "Xenopus" males and females to induce mating behavior and to breed these frogs in captivity at any time of the year. Amphibian frog "Xenopus laevis" also serves as an ideal model system for the study of the mechanisms of apoptosis. In fact, iodine and thyroxine stimulate the spectacular apoptosis of


title: "African clawed frog" content: the cells of the larval gills, tail and fins in amphibians metamorphosis, and stimulate the evolution of their nervous system transforming the aquatic, vegetarian tadpole into the terrestrial, carnivorous frog. Early work on sequencing of the "X. laevis" genome was started when the Wallingford and Marcotte labs obtained funding from the Texas Institute for Drug and Diagnostic Development (TI3D), in conjunction with projects funded by the National Institutes of Health. The work rapidly expanded to include "de novo" reconstruction of "X. laevis" transcripts, in collaboration with groups around the world donating Illumina Hi-Seq RNA sequencing datasets. Genome sequencing by the


title: "African clawed frog" content: Rokhsar and Harland groups (UC Berkeley) and by Taira and collaborators (University of Tokyo, Japan) gave a major boost to the project, which, with additional contributions from investigators in the Netherlands, Korea, Canada and Australia, led to publication of the genome sequence and its characterization in 2016. Xenbase is the Model Organism Database (MOD) with the full details and release information regarding the current "Xenopus laevis" genome (9.1). "Xenopus laevis" have been kept as pets and research subjects since as early as the 1950s. They are extremely hardy and long lived, having been known to live up to 20 or


title: "African clawed frog" content: even 30 years in captivity. African clawed frogs are frequently mislabeled as African dwarf frogs in pet stores. The astute pet owner will recognize the difference, however, because of the following characteristics: African clawed frogs are voracious predators and easily adapt to many habitats. For this reason, they can easily become a harmful invasive species. They can travel short distances to other bodies of water, and some have even been documented to survive mild freezes. They have been shown to devastate native populations of frogs and other creatures by eating their young. In 2003, "Xenopus laevis" frogs were discovered in


title: "African clawed frog" content: a pond at San Francisco's Golden Gate Park. Much debate now exists in the area on how to exterminate these creatures and keep them from spreading. It is unknown if these frogs entered the San Francisco ecosystem through intentional release or escape into the wild. San Francisco officials drained Lily Pond and fenced off the area to prevent the frogs from escaping to other ponds in the hopes they starve to death. Due to incidents in which these frogs were released and allowed to escape into the wild, African clawed frogs are illegal to own, transport or sell without a


title: "African clawed frog" content: permit in the following US states: Arizona, California, Kentucky, Louisiana, New Jersey, North Carolina, Oregon, Virginia, Hawaii, Nevada, and Washington state. However, it is legal to own "Xenopus laevis" in New Brunswick (Canada) and Ohio. Feral colonies of "Xenopus laevis" exist in South Wales, United Kingdom. The African clawed frog may be an important vector and the initial source of "Batrachochytrium dendrobatidis", a chytrid fungus that has been implicated in the drastic decline in amphibian populations in many parts of the world. Unlike in many other amphibian species (including the closely related western clawed frog) where this chytrid fungus causes


title: "African clawed frog" content: the disease Chytridiomycosis, it does not appear to affect the African clawed frog, making it an effective carrier. African clawed frog The African clawed frog ("Xenopus laevis", also known as the xenopus, African clawed toad, African claw-toed frog or the platanna) is a species of African aquatic frog of the family Pipidae. Its name is derived from the three short claws on each hind foot, which it uses to tear apart its food. The word "Xenopus" means "strange foot" and "laevis" means "smooth". The species is found throughout much of Sub-Saharan Africa (Nigeria and Sudan to South Africa), and in


title: "Tesla coil" content: Tesla coil A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high frequency alternating-current electricity. Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits. Tesla used these circuits to conduct innovative experiments in electrical lighting, phosphorescence, X-ray generation, high frequency alternating current phenomena, electrotherapy, and the transmission of electrical energy without wires. Tesla coil circuits were used commercially in sparkgap radio transmitters for wireless telegraphy until the 1920s, and in medical equipment such as electrotherapy and violet


title: "Tesla coil" content: ray devices. Today, their main use is for entertainment and educational displays, although small coils are still used as leak detectors for high vacuum systems. A Tesla coil is a radio frequency oscillator that drives an air-core double-tuned resonant transformer to produce high voltages at low currents. Tesla's original circuits as well as most modern coils use a simple spark gap to excite oscillations in the tuned transformer. More sophisticated designs use transistor or thyristor switches or vacuum tube electronic oscillators to drive the resonant transformer. Tesla coils can produce output voltages from 50 kilovolts to several million volts for


title: "Tesla coil" content: large coils. The alternating current output is in the low radio frequency range, usually between 50 kHz and 1 MHz. Although some oscillator-driven coils generate a continuous alternating current, most Tesla coils have a pulsed output; the high voltage consists of a rapid string of pulses of radio frequency alternating current. The common spark-excited Tesla coil circuit, shown below, consists of these components: The specialized transformer used in the Tesla coil circuit, called a resonant transformer, oscillation transformer or radio-frequency (RF) transformer, functions differently from an ordinary transformer used in AC power circuits. While an ordinary transformer is designed to


title: "Tesla coil" content: "transfer" energy efficiently from primary to secondary winding, the resonant transformer is also designed to "temporarily store" electrical energy. Each winding has a capacitance across it and functions as an LC circuit (resonant circuit, tuned circuit), storing oscillating electrical energy, analogously to a tuning fork. The primary coil "(L1)" consisting of a relatively few turns of heavy copper wire or tubing, is connected to a capacitor "(C1)" through the spark gap "(SG)". The secondary coil "(L2)" consists of many turns (hundreds to thousands) of fine wire on a hollow cylindrical form inside the primary. The secondary is not connected to


title: "Tesla coil" content: an actual capacitor, but it also functions as an LC circuit, the inductance of "(L2)" resonates with stray capacitance "(C2)", the sum of the stray parasitic capacitance between the windings of the coil, and the capacitance of the toroidal metal electrode attached to the high voltage terminal. The primary and secondary circuits are tuned so they resonate at the same frequency, they have the same resonant frequency. This allows them to exchange energy, so the oscillating current alternates back and forth between the primary and secondary coils. The peculiar design of the coil is dictated by the need to achieve


title: "Tesla coil" content: low resistive energy losses (high Q factor) at high frequencies, which results in the largest secondary voltages: The output circuit can have two forms: The circuit operates in a rapid, repeating cycle in which the supply transformer "(T)" charges the primary capacitor "(C1)" up, which then discharges in a spark through the spark gap, creating a brief pulse of oscillating current in the primary circuit which excites a high oscillating voltage across the secondary: This entire cycle takes place very rapidly, the oscillations dying out in a time of the order of a millisecond. Each spark across the spark gap


title: "Tesla coil" content: produces a pulse of damped sinusoidal high voltage at the output terminal of the coil. Each pulse dies out before the next spark occurs, so the coil generates a string of damped waves, not a continuous sinusoidal voltage. The high voltage from the supply transformer that charges the capacitor is a 50 or 60 Hz sine wave. Depending on how the spark gap is set, usually one or two sparks occur at the peak of each half-cycle of the mains current, so there are more than a hundred sparks per second. Thus the spark at the spark gap appears continuous,


title: "Tesla coil" content: as do the high voltage streamers from the top of the coil. The supply transformer "(T)" secondary winding is connected across the primary tuned circuit. It might seem that the transformer would be a leakage path for the RF current, damping the oscillations. However its large inductance gives it a very high impedance at the resonant frequency, so it acts as an open circuit to the oscillating current. If the supply transformer has inadequate leakage inductance, radio frequency chokes are placed in its secondary leads to block the RF current. To produce the largest output voltage, the primary and secondary


title: "Tesla coil" content: tuned circuits are adjusted to resonance with each other. The resonant frequencies of the primary and secondary circuits, formula_1 and formula_2, are determined by the inductance and capacitance in each circuit Generally the secondary is not adjustable, so the primary circuit is tuned, usually by a moveable tap on the primary coil L, until it resonates at the same frequency as the secondary Thus the condition for resonance between primary and secondary is A more detailed analysis of the circuit shows that resonance occurs, and the highest voltage is produced when the resonant frequencies of the primary and secondary are


title: "Tesla coil" content: slightly different. So a more precise condition for resonance is where formula_7 is the coupling coefficient of the transformer. However the Tesla transformer is very loosely coupled, and formula_7 is small, in the range 0.05 to 0.4. So the factor formula_9 is close to unity, 0.917 to 0.999, so the two resonant frequencies differ by 8% at most. Therefore, most sources state the transformer is resonant when the resonant frequencies of primary and secondary are equal. The resonant frequency of Tesla coils is in the low radio frequency (RF) range, usually between 50 kHz and 1 MHz. However, because of


title: "Tesla coil" content: the impulsive nature of the spark they produce broadband radio noise, and without shielding can be a significant source of RFI, interfering with nearby radio and television reception. In a resonant transformer the high voltage is produced by resonance; the output voltage is not proportional to the turns ratio, as in an ordinary transformer. It can be calculated approximately from conservation of energy. At the beginning of the cycle, when the spark starts, all of the energy in the primary circuit formula_10 is stored in the primary capacitor formula_11. If formula_12 is the voltage at which the spark gap breaks


title: "Tesla coil" content: down, which is usually close to the peak output voltage of the supply transformer "T", this energy is During the "ring up" this energy is transferred to the secondary circuit. Although some is lost as heat in the spark and other resistances, in modern coils, over 85% of the energy ends up in the secondary. At the peak (formula_14) of the secondary sinusoidal voltage waveform, all the energy in the secondary formula_15 is stored in the capacitance formula_16 between the ends of the secondary coil Assuming no energy losses, formula_18. Substituting into this equation and simplifying, the peak secondary voltage


title: "Tesla coil" content: is The second formula above is derived from the first using the resonance condition formula_19. Since the capacitance of the secondary coil is very small compared to the primary capacitor, the primary voltage is stepped up to a high value. The above peak voltage is only achieved in coils in which air discharges do not occur; in coils which produce sparks, like entertainment coils, the peak voltage on the terminal is limited to the voltage at which the air breaks down and becomes conductive. As the output voltage increases during each voltage pulse, it reaches the point where the air


title: "Tesla coil" content: next to the high voltage terminal ionizes and coronas, brush discharges and streamer arcs, break out from the terminal. This happens when the electric field strength exceeds the dielectric strength of the air, about 30 kV per centimeter. Since the electric field is greatest at sharp points and edges, air discharges start at these points on the high voltage terminal. The voltage on the high voltage terminal cannot increase above the air breakdown voltage, because additional electric charge pumped into the terminal from the secondary winding just escapes into the air. The output voltage of open-air Tesla coils is limited


title: "Tesla coil" content: to around several million volts by air breakdown, but higher voltages can be achieved by coils immersed in pressurized tanks of insulating oil. Most Tesla coil designs have a smooth spherical or toroidal shaped metal electrode on the high voltage terminal. The electrode serves as one plate of a capacitor, with the Earth as the other plate, forming the tuned circuit with the secondary winding. Although the "toroid" increases the secondary capacitance, which tends to reduce the peak voltage, its main effect is that its large diameter curved surface reduces the potential gradient (electric field) at the high voltage terminal,


title: "Tesla coil" content: increasing the voltage threshold at which air discharges such as corona and brush discharges occur. Suppressing premature air breakdown and energy loss allows the voltage to build to higher values on the peaks of the waveform, creating longer, more spectacular streamers. If the top electrode is large and smooth enough, the electric field at its surface may never get high enough even at the peak voltage to cause air breakdown, and air discharges will not occur. Some entertainment coils have a sharp "spark point" projecting from the torus to start discharges. The term "Tesla coil" is applied to a number


title: "Tesla coil" content: of high voltage resonant transformer circuits. Tesla coil circuits can be classified by the type of "excitation" they use, what type of circuit is used to apply current to the primary winding of the resonant transformer: Tesla circuits can also be classified by how many coils (inductors) they contain: Electrical oscillation and even resonant air-core transformer circuits had been explored and developed before Tesla, including Joseph Henry in Leyden jars (1850), and resonant transformers developed by Henry Rowland (1889) and Elihu Thomson (1890). Modern high-voltage enthusiasts usually build Tesla coils similar to some of Tesla's "later" 2-coil air-core designs. These


title: "Tesla coil" content: typically consist of a primary tank circuit, a series LC (inductance-capacitance) circuit composed of a high-voltage capacitor, spark gap and primary coil, and the secondary LC circuit, a series-resonant circuit consisting of the secondary coil plus a terminal capacitance or "top load". In Tesla's more advanced (magnifier) design, a third coil is added. The secondary LC circuit is composed of a tightly coupled air-core transformer secondary coil driving the bottom of a separate third coil helical resonator. Modern 2-coil systems use a single secondary coil. The top of the secondary is then connected to a topload terminal, which forms one


title: "Tesla coil" content: 'plate' of a capacitor, the other 'plate' being the earth (or "ground"). The primary LC circuit is tuned so that it resonates at the same frequency as the secondary LC circuit. The primary and secondary coils are magnetically coupled, creating a dual-tuned resonant air-core transformer. Earlier oil-insulated Tesla coils needed large and long insulators at their high-voltage terminals to prevent discharge in air. Later Tesla coils spread their electric fields over larger distances to prevent high electrical stresses in the first place, thereby allowing operation in free air. Most modern Tesla coils also use toroid-shaped output terminals. These are often


title: "Tesla coil" content: fabricated from spun metal or flexible aluminum ducting. The toroidal shape helps to control the high electrical field near the top of the secondary by directing sparks outward and away from the primary and secondary windings. A more complex version of a Tesla coil, termed a "magnifier" by Tesla, uses a more tightly coupled air-core resonance "driver" transformer (or "master oscillator") and a smaller, remotely located output coil (called the "extra coil" or simply the resonator) that has a large number of turns on a relatively small coil form. The bottom of the driver's secondary winding is connected to ground.


title: "Tesla coil" content: The opposite end is connected to the bottom of the extra coil through an insulated conductor that is sometimes called the transmission line. Since the transmission line operates at relatively high RF voltages, it is typically made of 1" diameter metal tubing to reduce corona losses. Since the third coil is located some distance away from the driver, it is not magnetically coupled to it. RF energy is instead directly coupled from the output of the driver into the bottom of the third coil, causing it to "ring up" to very high voltages. The combination of the two-coil driver and


title: "Tesla coil" content: third coil resonator adds another degree of freedom to the system, making tuning considerably more complex than that of a 2-coil system. The transient response for multiple resonance networks (of which the Tesla magnifier is a sub-set) has only recently been solved. It is now known that a variety of useful tuning "modes" are available, and in most operating modes the extra coil will ring at a different frequency than the master oscillator. Modern transistor or vacuum tube Tesla coils do not use a primary spark gap. Instead, the transistor(s) or vacuum tube(s) provide the switching or amplifying function necessary


title: "Tesla coil" content: to generate RF power for the primary circuit. Solid-state Tesla coils use the lowest primary operating voltage, typically between 155 and 800 volts, and drive the primary winding using either a single, half-bridge, or full-bridge arrangement of bipolar transistors, MOSFETs or IGBTs to switch the primary current. Vacuum tube coils typically operate with plate voltages between 1500 and 6000 volts, while most spark gap coils operate with primary voltages of 6,000 to 25,000 volts. The primary winding of a traditional transistor Tesla coil is wound around only the bottom portion of the secondary coil. This configuration illustrates operation of the


title: "Tesla coil" content: secondary as a pumped resonator. The primary 'induces' alternating voltage into the bottom-most portion of the secondary, providing regular 'pushes' (similar to providing properly timed pushes to a playground swing). Additional energy is transferred from the primary to the secondary inductance and top-load capacitance during each "push", and secondary output voltage builds (called 'ring-up'). An electronic feedback circuit is usually used to adaptively synchronize the primary oscillator to the growing resonance in the secondary, and this is the only tuning consideration beyond the initial choice of a reasonable top-load. In a dual resonant solid-state Tesla coil (DRSSTC), the electronic switching


title: "Tesla coil" content: of the solid-state Tesla coil is combined with the resonant primary circuit of a spark-gap Tesla coil. The resonant primary circuit is formed by connecting a capacitor in series with the primary winding of the coil, so that the combination forms a series tank circuit with a resonant frequency near that of the secondary circuit. Because of the additional resonant circuit, one manual and one adaptive tuning adjustment are necessary. Also, an interrupter is usually used to reduce the duty cycle of the switching bridge, to improve peak power capabilities; similarly, IGBTs are more popular in this application than bipolar


title: "Tesla coil" content: transistors or MOSFETs, due to their superior power handling characteristics. A current-limiting circuit is usually used to limit maximum primary tank current (which must be switched by the IGBT's) to a safe level. Performance of a DRSSTC can be comparable to a medium-power spark-gap Tesla coil, and efficiency (as measured by spark length versus input power) can be significantly greater than a spark-gap Tesla coil operating at the same input power. A large Tesla coil of more modern design often operates at very high peak power levels, up to many megawatts (millions of watts). It is therefore adjusted and operated


title: "Tesla coil" content: carefully, not only for efficiency and economy, but also for safety. If, due to improper tuning, the maximum voltage point occurs below the terminal, along the secondary coil, a discharge (spark) may break out and damage or destroy the coil wire, supports, or nearby objects. Tesla experimented with these, and many other, circuit configurations (see right). The Tesla coil primary winding, spark gap and tank capacitor are connected in series. In each circuit, the AC supply transformer charges the tank capacitor until its voltage is sufficient to break down the spark gap. The gap suddenly fires, allowing the charged tank


title: "Tesla coil" content: capacitor to discharge into the primary winding. Once the gap fires, the electrical behavior of either circuit is identical. Experiments have shown that neither circuit offers any marked performance advantage over the other. However, in the typical circuit, the spark gap's short circuiting action prevents high-frequency oscillations from 'backing up' into the supply transformer. In the alternate circuit, high amplitude high frequency oscillations that appear across the capacitor also are applied to the supply transformer's winding. This can induce corona discharges between turns that weaken and eventually destroy the transformer's insulation. Experienced Tesla coil builders almost exclusively use the top


title: "Tesla coil" content: circuit, often augmenting it with low pass filters (resistor and capacitor (RC) networks) between the supply transformer and spark gap to help protect the supply transformer. This is especially important when using transformers with fragile high-voltage windings, such as neon sign transformers (NSTs). Regardless of which configuration is used, the HV transformer must be of a type that self-limits its secondary current by means of internal leakage inductance. A normal (low leakage inductance) high-voltage transformer must use an external limiter (sometimes called a ballast) to limit current. NSTs are designed to have high leakage inductance to limit their short circuit


title: "Tesla coil" content: current to a safe level. The primary coil's resonant frequency is tuned to that of the secondary, by using low-power oscillations, then increasing the power (and retuning if necessary) until the system operates properly at maximum power. While tuning, a small projection (called a "breakout bump") is often added to the top terminal in order to stimulate corona and spark discharges (sometimes called streamers) into the surrounding air. Tuning can then be adjusted so as to achieve the longest streamers at a given power level, corresponding to a frequency match between the primary and secondary coil. Capacitive "loading" by the


title: "Tesla coil" content: streamers tends to lower the resonant frequency of a Tesla coil operating under full power. A toroidal topload is often preferred to other shapes, such as a sphere. A toroid with a major diameter that is much larger than the secondary diameter provides improved shaping of the electrical field at the topload. This provides better protection of the secondary winding (from damaging streamer strikes) than a sphere of similar diameter. And, a toroid permits fairly independent control of topload capacitance versus spark breakout voltage. A toroid's capacitance is mainly a function of its major diameter, while the spark breakout voltage


title: "Tesla coil" content: is mainly a function of its minor diameter. A grid dip oscillator (GDO) is sometimes used to help facilitate initial tuning and aid in design. The resonant frequency of the secondary can be difficult to determine except by using a GDO or other experimental method, whereas the physical properties of the primary more closely represent first-order approximations of RF tank design. In this schema the secondary is built somewhat arbitrarily in imitation of other successful designs, or entirely so with supplies on hand, it's resonant frequency is measured and the primary designed to suit. While generating discharges, electrical energy from


title: "Tesla coil" content: the secondary and toroid is transferred to the surrounding air as electrical charge, heat, light, and sound. The process is similar to charging or discharging a capacitor, except that a Tesla coil uses AC instead of DC. The current that arises from shifting charges within a capacitor is called a displacement current. Tesla coil discharges are formed as a result of displacement currents as pulses of electrical charge are rapidly transferred between the high-voltage toroid and nearby regions within the air (called space charge regions). Although the space charge regions around the toroid are invisible, they play a profound role


title: "Tesla coil" content: in the appearance and location of Tesla coil discharges. When the spark gap fires, the charged capacitor discharges into the primary winding, causing the primary circuit to oscillate. The oscillating primary current creates an oscillating magnetic field that couples to the secondary winding, transferring energy into the secondary side of the transformer and causing it to oscillate with the toroid capacitance to ground. Energy transfer occurs over a number of cycles, until most of the energy that was originally in the primary side is transferred to the secondary side. The greater the magnetic coupling between windings, the shorter the time


title: "Tesla coil" content: required to complete the energy transfer. As energy builds within the oscillating secondary circuit, the amplitude of the toroid's RF voltage rapidly increases, and the air surrounding the toroid begins to undergo dielectric breakdown, forming a corona discharge. As the secondary coil's energy (and output voltage) continue to increase, larger pulses of displacement current further ionize and heat the air at the point of initial breakdown. This forms a very electrically conductive "root" of hotter plasma, called a leader, that projects outward from the toroid. The plasma within the leader is considerably hotter than a corona discharge, and is considerably


title: "Tesla coil" content: more conductive. In fact, its properties are similar to an electric arc. The leader tapers and branches into thousands of thinner, cooler, hair-like discharges (called streamers). The streamers look like a bluish 'haze' at the ends of the more luminous leaders. The streamers transfer charge between the leaders and toroid to nearby space charge regions. The displacement currents from countless streamers all feed into the leader, helping to keep it hot and electrically conductive. The primary break rate of sparking Tesla coils is slow compared to the resonant frequency of the resonator-topload assembly. When the switch closes, energy is transferred


title: "Tesla coil" content: from the primary LC circuit to the resonator where the voltage rings up over a short period of time up culminating in the electrical discharge. In a spark gap Tesla coil, the primary-to-secondary energy transfer process happens repetitively at typical pulsing rates of 50–500 times per second, depending on the frequency of the input line voltage. At these rates, previously-formed leader channels do not get a chance to fully cool down between pulses. So, on successive pulses, newer discharges can build upon the hot pathways left by their predecessors. This causes incremental growth of the leader from one pulse to


title: "Tesla coil" content: the next, lengthening the entire discharge on each successive pulse. Repetitive pulsing causes the discharges to grow until the average energy available from the Tesla coil during each pulse balances the average energy being lost in the discharges (mostly as heat). At this point, dynamic equilibrium is reached, and the discharges have reached their maximum length for the Tesla coil's output power level. The unique combination of a rising high-voltage radio frequency envelope and repetitive pulsing seem to be ideally suited to creating long, branching discharges that are considerably longer than would be otherwise expected by output voltage considerations alone.


title: "Tesla coil" content: High-voltage, low-energy discharges create filamentary multibranched discharges which are purplish-blue in colour. High-voltage, high-energy discharges create thicker discharges with fewer branches, are pale and luminous, almost white, and are much longer than low-energy discharges, because of increased ionisation. A strong smell of ozone and nitrogen oxides will occur in the area. The important factors for maximum discharge length appear to be voltage, energy, and still air of low to moderate humidity. There are comparatively few scientific studies about the initiation and growth of pulsed lower-frequency RF discharges, so some aspects of Tesla coil air discharges are not as well understood


title: "Tesla coil" content: when compared to DC, power-frequency AC, HV impulse, and lightning discharges. Today, although small Tesla coils are used as leak detectors in scientific high vacuum systems and igniters in arc welders, their main use is entertainment and educational displays. Tesla coils are displayed as attractions at science museums and electronics fairs, and are used to demonstrate principles of high frequency electricity in science classes in schools and colleges. Since they are simple enough for an amateur to make, Tesla coils are a popular student science fair project, and are homemade by a large worldwide community of hobbyists. Builders of Tesla


title: "Tesla coil" content: coils as a hobby are called "coilers". They attend "coiling" conventions where they display their home-made Tesla coils and other high voltage devices. Low-power Tesla coils are also sometimes used as a high-voltage source for Kirlian photography The world's largest currently existing Tesla coil is a 130,000-watt unit, part of a sculpture titled "Electrum" owned by Alan Gibbs and currently resides in a private sculpture park at Kakanui Point near Auckland, New Zealand. A very large Tesla coil, designed and built by Syd Klinge, is shown every year at the Coachella Valley Music and Arts Festival, in Coachella, Indio, California,


title: "Tesla coil" content: USA. Austin Richards, a physicist in California, created a metal Faraday Suit in 1997 that protects him from Tesla coil discharges. In 1998, he named the character in the suit Doctor MegaVolt and has performed all over the world and at Burning Man nine different years. Tesla coils can also be used to generate sounds, including music, by modulating the system's effective "break rate" (i.e., the rate and duration of high power RF bursts) via MIDI data and a control unit. The actual MIDI data is interpreted by a microcontroller which converts the MIDI data into a PWM output which


title: "Tesla coil" content: can be sent to the Tesla coil via a fiber optic interface. The YouTube video Super Mario Brothers theme in stereo and harmony on two coils shows a performance on matching solid state coils operating at 41 kHz. The coils were built and operated by designer hobbyists Jeff Larson and Steve Ward. The device has been named the Zeusaphone, after Zeus, Greek god of lightning, and as a play on words referencing the Sousaphone. The idea of playing music on the singing Tesla coils flies around the world and a few followers<ref name="https://www.youtube.com/user/teslamusicband">Tesla Music Band</ref> continue the work of initiators.


title: "Tesla coil" content: An extensive outdoor musical concert has demonstrated using Tesla coils during the Engineering Open House (EOH) at the University of Illinois at Urbana–Champaign. The Icelandic artist Björk used a Tesla coil in her song "Thunderbolt" as the main instrument in the song. The musical group ArcAttack uses modulated Tesla coils and a man in a chain-link suit to play music. Scientists working with high vacuum systems test for the presence of tiny pin holes in the apparatus (especially a newly blown piece of glassware) using high-voltage discharges produced by a small handheld Tesla coil. When the system is evacuated the


title: "Tesla coil" content: high voltage electrode of the coil is played over the outside of the apparatus. At low pressures, air is more easily ionized and thus conducts electricity better than atmospheric pressure air. Therefore, the discharge travels through any pin hole immediately below it, producing a corona discharge inside the evacuated space which illuminates the hole, indicating points that need to be annealed or reblown before they can be used in an experiment. The high voltage radio frequency (RF) discharges from the output terminal of a Tesla coil pose a unique hazard not found in other high voltage equipment: when passed through


title: "Tesla coil" content: the body they often do not cause the painful sensation and muscle contraction of electric shock, as lower frequency AC or DC currents do. The nervous system is insensitive to currents with frequencies over 10 – 20 kHz. It is thought that the reason for this is that a certain minimum number of ions must be driven across a nerve cell's membrane by the imposed voltage to trigger the nerve cell to depolarize and transmit an impulse. At radio frequencies, there is insufficient time during a half-cycle for enough ions to cross the membrane before the alternating voltage reverses. The


title: "Tesla coil" content: danger is that since no pain is felt, experimenters often assume the currents are harmless. Teachers and hobbyists demonstrating small Tesla coils often impress their audience by touching the high voltage terminal or allowing the streamer arcs to pass through their body. If the arcs from the high voltage terminal strike the bare skin, they can cause deep-seated burns called "RF burns". This is often avoided by allowing the arcs to strike a piece of metal held in the hand, or a thimble on a finger, instead. The current passes from the metal into the person's hand through a wide


title: "Tesla coil" content: enough surface area to avoid causing burns. Often no sensation is felt, or just a warmth or tingling. However this does not mean the current is harmless. Even a small Tesla coil produces many times the electrical energy necessary to stop the heart, if the frequency happens to be low enough to cause ventricular fibrillation. A minor misadjustment of the coil could result in electrocution. In addition, the RF current heats the tissues it passes through. Tesla coil currents, applied directly to the skin by electrodes, were used in the early 20th century for deep body tissue heating in the


title: "Tesla coil" content: medical field of longwave "diathermy". The amount of heating depends on the current density, which depends on the power output of the Tesla coil and the cross-sectional area of the path the current takes through the body to ground. Particularly if it passes through narrow structures such as blood vessels or joints it may raise the local tissue temperature to hyperthermic levels, "cooking" internal organs or causing other injuries. International ICNIRP safety standards for RF current in the body in the Tesla coil frequency range of 0.1 - 1 MHz specify a maximum current density of 0.2 mA per square


title: "Tesla coil" content: centimeter and a maximum power absorption rate (SAR) in tissue of 4 W/kg in limbs and 0.8 W/kg average over the body. Even low power Tesla coils could exceed these limits, and it is generally impossible to determine the threshold current where bodily injury begins. Being struck by arcs from a high power (> 1000 watt) Tesla coil is likely to be fatal. Another reported hazard of this practice is that arcs from the high voltage terminal often strike the primary winding of the coil. This momentarily creates a conductive path for the lethal 50/60 Hz primary current from the


title: "Tesla coil" content: supply transformer to reach the output terminal. If a person is connected to the output terminal at the time, either by touching it or allowing arcs from the terminal to strike the person's body, then the high primary current could pass through the conductive ionized air path, through the body to ground, causing electrocution. An erroneous explanation for the absence of electric shock that has persisted among Tesla coil hobbyists is that the high frequency currents travel through the body close to the surface, and thus do not penetrate to vital organs or nerves, due to an electromagnetic phenomenon called


title: "Tesla coil" content: "skin effect". This theory is false. RF current does tend to flow on the surface of conductors due to skin effect, but the depth to which it penetrates, called "skin depth", depends on the resistivity and permittivity of the material as well as the frequency. Although skin effect limits currents of Tesla coil frequencies to the outer fraction of a millimeter in metal conductors, the skin depth of the current in body tissue is much deeper due to its higher resistivity and lower permittivity. The depth of penetration of currents of Tesla frequency (0.1 - 1 MHz) in human tissues


title: "Tesla coil" content: is roughly 24 to 72 cm (9 to 28 inches). Since even the deepest tissues are closer than this to the surface, skin effect has little influence on the path of the current through the body; it tends to take the path of minimum electrical impedance to ground, and can easily pass through the core of the body. In the medical therapy called longwave diathermy, carefully controlled RF current of Tesla frequencies was used for decades for deep tissue warming, including heating internal organs such as the lungs. Modern shortwave diathermy machines use a higher frequency of 27 MHz, which


title: "Tesla coil" content: would have a correspondingly smaller skin depth, yet these frequencies are still able to penetrate deep body tissues. Tesla coil A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high frequency alternating-current electricity. Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits. Tesla used these circuits to conduct innovative experiments in electrical lighting, phosphorescence, X-ray generation, high frequency alternating current phenomena, electrotherapy, and the transmission of electrical energy without wires. Tesla coil circuits were used commercially in


title: Banksia content: Banksia Banksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads. "Banksias" range in size from prostrate woody shrubs to trees up to 30 metres tall. They are found in a wide variety of landscapes; sclerophyll forest, (occasionally) rainforest, shrubland, and some more arid landscapes, though not in Australia's deserts. Heavy producers of nectar, "banksias" are a vital part of the food chain in the Australian bush. They are an important food source for all sorts of


title: Banksia content: nectarivorous animals, including birds, bats, rats, possums, stingless bees and a host of invertebrates. Furthermore, they are of economic importance to Australia's nursery and cut flower industries. However these plants are threatened by a number of processes including land clearing, frequent burning and disease, and a number of species are rare and endangered. "Banksias" grow as trees or woody shrubs. Trees of the largest species, "B. integrifolia" (coast banksia) and "B. seminuda" (river banksia), often grow over 15 metres tall, some even grow to standing 30 metres tall. "Banksia" species that grow as shrubs are usually erect, but there are


title: Banksia content: several species that are prostrate, with branches that grow on or below the soil. The leaves of "Banksia" vary greatly between species. Sizes vary from the narrow, 1–1½ centimetre long needle-like leaves of "B. ericifolia" (heath-leaved banksia), to the very large leaves of "B. grandis" (bull banksia), which may be up to 45 centimetres long. The leaves of most species have serrated edges, but a few, such as "B. integrifolia", do not. Leaves are usually arranged along the branches in irregular spirals, but in some species they are crowded together in whorls. Many species have differing juvenile and adult leaves


title: Banksia content: (e.g., "Banksia integrifolia" has large serrated juvenile leaves). The flowers are arranged in flower spikes or capitate flower heads. The character most commonly associated with "Banksia" is the flower spike, an elongated inflorescence consisting of a woody axis covered in tightly-packed pairs of flowers attached at right angles. A single flower spike generally contains hundreds or even thousands of flowers; the most recorded is around 6000 on inflorescences of "B. grandis". Not all "Banksia" have an elongate flower spike, however: the members of the small "Isostylis" complex have long been recognised as "Banksia"s in which the flower spike has been


title: Banksia content: reduced to a head; and recently the large genus "Dryandra" has been found to have arisen from within the ranks of "Banksia", and sunk into it as "B." ser. "Dryandra". They similarly have capitate flower heads rather than spikes. "Banksia" flowers are usually a shade of yellow, but orange, red, pink and even violet flowers also occur. The colour of the flowers is determined by the colour of the perianth parts and often the style. The style is much longer than the perianth, and is initially trapped by the upper perianth parts. These are gradually released over a period of


title: Banksia content: days, either from top to bottom or from bottom to top. When the styles and perianth parts are different colours, the visual effect is of a colour change sweeping along the spike. This can be most spectacular in "B. prionotes" (acorn banksia) and related species, as the white inflorescence in bud becomes a brilliant orange. In most cases, the individual flowers are tall, thin saccate (sack-shaped) in shape. Occasionally, multiple flower spikes can form. This is most often seen in "Banksia marginata" and "B. ericifolia" "(pictured right)". As the flower spikes or heads age, the flower parts dry up and


title: Banksia content: may turn shades of orange, tan or dark brown colour, before fading to grey over a period of years. In some species, old flower parts are lost, revealing the axis; in others, the old flower parts may persist for many years, giving the fruiting structure a hairy appearance. Old flower spikes are commonly referred to as "cones", although they are not technically cones according to the botanical definition of the term: cones only occur in conifers and cycads. Despite the large number of flowers per inflorescence, only a few of them ever develop fruit, and in some species a flower


title: Banksia content: spike will set no fruit at all. The fruit of "Banksia" is a woody follicle embedded in the axis of the inflorescence. In many species, the resulting structure is a massive woody structure commonly called a cone. Each follicle consists of two horizontal valves that tightly enclose the seeds. The follicle opens to release the seed by splitting along the suture, and in some species each valve splits too. In some species the follicles open as soon as the seed is mature, but in most species most follicles open only after stimulated to do so by bushfire. Each follicle usually


title: Banksia content: contains one or two small seeds, each with a wedge-shaped papery wing that causes it to spin as it falls to the ground. Specimens of "Banksia" were first collected by Sir Joseph Banks and Dr Daniel Solander, naturalists on the "Endeavour" during Lieutenant (later Captain) James Cook's first voyage to the Pacific Ocean. Cook landed on Australian soil for the first time on 29 April 1770, at a place that he later named Botany Bay in recognition of "the great quantity of plants Mr Banks and Dr Solander found in this place". Over the next seven weeks, Banks and Solander


title: Banksia content: collected thousands of plant specimens, including the first specimens of a new genus that would later be named "Banksia" in Banks' honour. Four species were present in this first collection: "B. serrata" (Saw Banksia), "B. integrifolia" (Coast Banksia), "B. ericifolia" (Heath-leaved Banksia) and "B. robur" (Swamp Banksia). In June the ship was careened at Endeavour River, where specimens of "B. dentata" (Tropical Banksia) were collected. The genus "Banksia" was finally described and named by Carolus Linnaeus the Younger in his April 1782 publication "Supplementum Plantarum"; hence the full name for the genus is ""Banksia" L.f.". Linnaeus placed the genus in


title: Banksia content: class Tetrandra, order Monogynia of his father's classification, and named it in honour of Banks. The name "Banksia" had in fact already been published in 1775 as "Banksia" J.R.Forst & G.Forst, referring to some New Zealand species that the Forsters had collected during Cook's second voyage. However Linnaeus incorrectly attributed the Forsters' specimens to the genus "Passerina", and therefore considered the name "Banksia" available for use. By the time Joseph Gaertner corrected Banks' error in 1788, "Banksia" L.f. was widely known and accepted, so Gaertner renamed "Banksia" J.R.Forst & G.Forst to "Pimelea", a name previously chosen for the genus by


title: Banksia content: Banks and Solander. The first specimens of a "Dryandra" were collected by Archibald Menzies, surgeon and naturalist to the Vancouver Expedition. At the request of Joseph Banks, Menzies collected natural history specimens wherever possible during the voyage. During September and October 1791, while the expedition were anchored at King George Sound, he collected numerous plant specimens, including the first specimens of "Dryandra ("now" Banksia) sessilis" (Parrotbush) and "D. ("now" Banksia) pellaeifolia". Upon Menzies' return to England, he turned his specimens over to Banks; as with most other specimens in Banks' library, they remained undescribed for many years. Robert Brown gave


title: Banksia content: a lecture, naming the new genus "Dryandra" in 1809, however Joseph Knight published the name "Josephia" before Brown published his paper with the description of "Dryandra". Brown ignored Knight's name, as did subsequent botanists. In 1891, Otto Kuntze proposed to enforce the right of precedent of "Banksia" J.R.Forst & G.Forst, renaming "Pimelea" to "Banksia", and proposing the name "Sirmuellera" Kuntze in place of "Banksia" L.f. This challenge failed, as did James Britten's 1905 challenge. In 1940, "Banksia" L.f. was formally conserved against "Banksia" J.R.Forst. & G.Forst by Thomas Sprague. "Banksia" belongs to the family Proteaceae, subfamily Grevilleoideae, and tribe Banksieae.


title: Banksia content: There are around 170 species. The closest relatives of "Banksia" are two genera of rainforest trees in North Queensland ("Musgravea" and "Austromuellera"). Alex George arranged the genus into two subgenera—subgenus "Isostylis" (containing "B. ilicifolia", "B. oligantha" and "B. cuneata") and subgenus "Banksia" (containing all other species except those he considered dryandras)—in his 1981 monograph and 1999 treatment for the Flora of Australia series. He held that flower morphology was the key to relationships in the genus. Austin Mast and Kevin Thiele published the official merging of "Dryandra" within "Banksia" in 2007, recalibrating the genus into subgenus "Banksia" and subgenus "Spathulatae".