Mistletoe is the English common name for most obligate hemiparasitic plants in the order Santalales. They are attached to their host tree or shrub by a structure called the haustorium, through which they extract water and nutrients from the host plant. Their parasitic lifestyle have led to some dramatic changes in their metabolism.
The name mistletoe originally referred to the species Viscum album (European mistletoe, of the family Santalaceae in the order Santalales); it is the only species native to the British Isles and much of Europe. A separate species, Viscum cruciatum, occurs in Southwest Spain and Southern Portugal, as well as Morocco (North Africa) and southern Africa.
Over the centuries, the term has been broadened to include many other species of parasitic plants with similar habits, found in other parts of the world, that are classified in different genera and even families—such as the Misodendraceae and the Loranthaceae.
In particular, the eastern mistletoe native to North America, Phoradendron leucarpum, belongs to a distinct genus of the family Santalaceae. The genus Viscum is not native to North America, but Viscum album has been introduced to California. European mistletoe has smooth-edged, oval, evergreen leaves borne in pairs along the woody stem, and waxy, white berries that it bears in clusters of two to six. The Eastern mistletoe of North America is similar, but has shorter, broader leaves and longer clusters of 10 or more berries.
The word 'mistletoe' derives from the older form 'mistle' adding the Old English word tān (twig). 'Mistle' is common Germanic (Old High German mistil, Middle High German mistel, Old English mistel, Old Norse mistil). Further etymology is uncertain, but may be related to the Germanic base for 'mash'.
Parasitism has evolved at least 12 times among the vascular plants . Molecular data show the mistletoe habit has evolved independently five times within the Santalales—first in the Misodendraceae, but also in the Loranthaceae and three times in the Santalaceae (in the former Santalalean families Eremolepidaceae and Viscaceae, and the tribe Amphorogyneae). 
The largest family of mistletoes, the Loranthaceae, has 73 genera and over 900 species. Subtropical and tropical climates have markedly more mistletoe species; Australia has 85, of which 71 are in Loranthaceae, and 14 in Santalaceae.
Mistletoe species grow on a wide range of host trees, some of which experience side effects including reduced growth, stunting, and loss of infested outer branches. A heavy infestation may also kill the host plant. Viscum album successfully parasitizes more than 200 tree and shrub species.
All mistletoe species are hemiparasites, because they do perform at least a little photosynthesis for at least a short period of their life cycle. However, in some species its contribution is very nearly zero. For example, some species, such as Viscum minimum, that parasitize succulents, commonly species of Cactaceae or Euphorbiaceae, grow largely within the host plant, with hardly more than the flower and fruit emerging. Once they have germinated and attached to the circulatory system of the host, their photosynthesis reduces so far that it becomes insignificant.
Most of the Viscaceae bear evergreen leaves that photosynthesise effectively, and photosynthesis proceeds within their green, fleshy stems as well. Some species, such as Viscum capense, are adapted to semi-arid conditions and their leaves are vestigial scales, hardly visible without detailed morphological investigation. Therefore their photosynthesis and transpiration only take place in their stems, limiting their demands on the host's supply of water, but also limiting their intake of carbon dioxide for photosynthesis. Accordingly their contribution to the host's metabolic balance becomes trivial and the idle parasite may become quite yellow as it grows, having practically given up photosynthesis.
At another extreme other species have vigorous green leaves. Not only do they photosynthesize actively, but a heavy infestation of mistletoe plants may take over whole host tree branches, sometimes killing practically the entire crown and replacing it with their own growth. In such a tree the host is relegated purely to the supply of water and mineral nutrients and the physical support of the trunk. Such a tree may survive as a Viscum community for years; it resembles a totally unknown species unless one examines it closely, because its foliage does not look like that of any tree. An example of a species that behaves in this manner is Viscum continuum.
A mistletoe seed germinates on the branch of a host tree or shrub, and in its early stages of development it is independent of its host. It commonly has two or even four embryos, each producing its hypocotyl, that grows towards the bark of the host under the influence of light and gravity, and potentially each forming a mistletoe plant in a clump. Possibly as an adaptation to assist in guiding the process of growing away from the light, the adhesive on the seed tends to darken the bark. On having made contact with the bark, the hypocotyl, with only a rudimentary scrap of root tissue at its tip penetrates it, a process that may take a year or more. In the meantime the plant is dependent on its own photosynthesis. Only after it reaches the host's conductive tissue can it begin to rely on the host for its needs. Later it forms a haustorium that penetrates the host tissue and takes water and nutrients from the host plant.
Species more or less obligate include the leafless quintral, Tristerix aphyllus, which lives deep inside the sugar-transporting tissue of a spiny cactus, appearing only to show its tubular red flowers, and the genus Arceuthobium (dwarf mistletoe; Santalaceae) which has reduced photosynthesis; as an adult, it manufactures only a small proportion of the sugars it needs from its own photosynthesis, but as a seedling actively photosynthesizes until a connection to the host is established.
Most mistletoe seeds are spread by birds that eat the 'seeds' (in actuality drupes). Of the many bird species that feed on them, the mistle thrush is the best-known in Europe, the Phainopepla in southwestern North America, and Dicaeum of Asia and Australia. Depending on the species of mistletoe and the species of bird, the seeds are regurgitated from the crop, excreted in their droppings, or stuck to the bill, from which the bird wipes it onto a suitable branch. The seeds are coated with a sticky material called viscin. Some viscin remains on the seed and when it touches a stem, it sticks tenaciously. The viscin soon hardens and attaches the seed firmly to its future host, where it germinates and its haustorium penetrates the sound bark.
Specialist mistletoe eaters have adaptations that expedite the process; some pass the seeds through their unusually shaped digestive tracts so fast that a pause for defecation of the seeds is part of the feeding routine. Others have adapted patterns of feeding behavior; the bird grips the fruit in its bill and squeezes the sticky-coated seed out to the side. The seed sticks to the beak and the bird wipes it off onto the branch.
Once a mistletoe plant is established on its host, it usually is possible to save a valuable branch by pruning and judicious removal of the wood invaded by the haustorium, if the infection is caught early enough. Some species of mistletoe can regenerate if the pruning leaves any of the haustorium alive in the wood.
Some mistletoe plants are toxic though their effects are not usually fatal. The active substances are Phoratoxin (in Phoradendron) and Tyramine (in Viscum) and their effects include blurred vision, diarrhoea, nausea and vomiting. Less commonly they cause cardiac problems; seizures, hypertension, and even cardiac arrest. Toxins are more concentrated in the leaves and berries of the plant, with teas prepared from the plant being particularly dangerous. While adults may suffer little effect, these are more pronounced in small children and in animals. There are 1500 species of mistletoe, varying widely in toxicity; the European mistletoe (Viscum Album) is more toxic than the American mistletoe (Phoradendron serotinum), though concerns regarding toxicity are more prevalent in the US. 
Mistletoe has been used historically in medicine for its supposed value in treating arthritis, high blood pressure, epilepsy and infertility: Conversely, it can cause vasoconstriction and bradycardia, and is also used as an illegal abortifacient Mistletoe is currently used as a complementary medicine for the treatment of cancer (though its use is not approved by the FDA) and as a veterinary herbal medicine.
Mistletoes are often considered pests that kill trees and devalue natural habitats, but some species have recently been recognized as ecological keystone species, organisms that have a disproportionately pervasive influence over their community. A broad array of animals depend on mistletoe for food, consuming the leaves and young shoots, transferring pollen between plants and dispersing the sticky seeds. In western North America their juicy berries are eaten and spread by birds (notably Phainopepla, or silky-flycatcher) while in Australia the mistletoebird behaves similarly. When eaten, some seeds pass unharmed through their digestive systems; if the birds’ droppings happen to land on a suitable branch, the seeds may stick long enough to germinate. As the plants mature, they grow into masses of branching stems which suggest the popular name "witches’ brooms". The dense evergreen witches' brooms formed by the dwarf mistletoes (Arceuthobium species) of western North America also make excellent locations for roosting and nesting of the northern spotted owl and the marbled murrelet. In Australia the diamond firetail and painted honeyeater are recorded as nesting in different mistletoes. This behavior is probably far more widespread than currently recognized; more than 240 species of birds that nest in foliage in Australia have been recorded nesting in mistletoe, representing more than 75% of the resident birds.
A study of mistletoe in junipers concluded that more juniper berries sprout in stands where mistletoe is present, as the mistletoe attracts berry-eating birds which also eat juniper berries. Such interactions lead to dramatic influences on diversity, as areas with greater mistletoe densities support higher diversities of animals. Thus, rather than being a pest, mistletoe can have a positive effect on biodiversity, providing high quality food and habitat for a broad range of animals in forests and woodlands worldwide.
Mistletoe is relevant to several cultures.
Pre-Christian cultures regarded the white berries as symbols of male fertility, with the seeds resembling semen. The Celts, particularly, saw mistletoe as the semen of Taranis, while the Ancient Greeks referred to mistletoe as "oak sperm." Also in Ancient Greek mythology mistletoe was used by the hero Aeneas to access the underworld.. Mistletoe played an important role in Druidic mythology in the Ritual of Oak and Mistletoe. In Norse Mythology, Loki tricked the blind god Hodur into murdering his own twin brother Balder with an arrow made of mistletoe wood, being the only plant to which Balder was vulnerable. Some versions of the story have mistletoe becoming a symbol of peace and friendship to compensate for its part in the murder.
In the Christian era, mistletoe in the Western world became associated with Christmas as a decoration under which lovers are expected to kiss, as well as with protection from witches and demons. Mistletoe continued to be associated with fertility and vitality through the Middle Ages, and by the 18th century it had also become incorporated into Christmas celebrations around the world. The custom of kissing under the mistletoe is referred to as popular among servants in late 18th century England: the serving class of Victorian England is credited with perpetuating the tradition. The tradition dictated that a man was allowed to kiss any woman standing underneath mistletoe, and that bad luck would befall any woman who refused the kiss. One variation on the tradition stated that with each kiss a berry was to be plucked from the mistletoe, and the kissing must stop after all the berries had been removed. People have reportedly been poisoned and died from consuming mistletoe.
In Germany, the Christmas tradition is that people who kiss under mistletoe will have an enduring love or are bound to marry one another.
From at least the mid-19th century, Caribbean herbalists of African descent have referred to mistletoe as "god-bush".
One of the earliest references to mistletoe traditions in popular music is the 1952 hit 'I Saw Mommy Kissing Santa Claus', which was originally sung by Jimmy Boyd and has been covered by many singers. The song was written by British songwriter Tommie Connor and recorded in the US. The 1958 US hit 'Rockin' Around The Christmas Tree' refers to couples wanting to stop beneath the mistletoe. In 1988, the British singer Cliff Richard released a popular Christmas song called 'Mistletoe and Wine'. More recent Christmas songs referring to mistletoe traditions include 'Merry Christmas Everyone' by Shakin' Stevens (1991), 'All I Want For Christmas Is You' written and performed by Mariah Carey (1994) and 'Mistletoe' by Justin Bieber (2011).
In the Asterix franchise, mistletoe is the main ingredient of the 'Magic Potion' that endows the Gauls with superhuman prowess (strength, etc.), that allows the Gaulish village to keep the Romans at bay.
In the popular roleplaying game Dungeons & Dragons, druids use mistletoe as the default focus item for casting spells.
Anthroposophic medicine (or anthroposophical medicine) is a form of alternative medicine. Devised in the 1920s by Rudolf Steiner (1861–1925) in conjunction with Ita Wegman (1876–1943), anthroposophical medicine is based on occult notions and draws on Steiner's spiritual philosophy, which he called anthroposophy. Practitioners employ a variety of treatment techniques based upon anthroposophic precepts, including massage, exercise, counselling, and substances.Many drug preparations used in anthroposophic medicine are ultra-diluted substances, similar to those used in homeopathy. Homeopathic remedies are not medically effective and are generally considered harmless, except when used as a substitute for a scientifically proven and effective cure. In certain European countries, people with cancer are sometimes prescribed remedies made from specially harvested mistletoe, but research has found no convincing evidence of clinical benefit. Some anthroposophic doctors oppose childhood vaccination, and this has led to preventable outbreaks of disease.Anthroposophic medicine departs from fundamental biological principles in several respects. For example, Steiner said that the heart does not pump blood but that blood propels itself along. Anthroposophic medicine also proposes that patients' past lives may influence their illness and that the course of an illness is subject to karmic destiny. Professor of complementary medicine Edzard Ernst and other physicians and scientists including Simon Singh and David Gorski have characterized anthroposophic medicine as pseudoscientific quackery with no basis in reason or logic.Arceuthobium
The genus Arceuthobium, commonly called dwarf mistletoes, is a genus of 26 species of parasitic plants that parasitize members of Pinaceae and Cupressaceae in North America, Central America, Asia, Europe, and Africa. Of the 42 species, 39 and 21 are endemic to North America and the United States, respectively. They all have very reduced shoots and leaves (mostly reduced to scales) with the bulk of the plant living under the host's bark. Recently the number of species within the genus has been reduced to 26 as a result of more detailed genetic analysis.Christmas at Our House
Christmas at Our House is the seventeenth studio album by the American country artist Barbara Mandrell. The album was released in October 1984 on MCA Records and was produced by Tom Collins. It was Mandrell's first album of Christmas music.Haustorium
In botany and mycology, a haustorium (plural haustoria) it is root like structure or also a structure that grows into or around another structure to absorb water or nutrients. In botany, this may refer to a cotyledon, or to the root of a parasitic plant (such as the broomrape family or mistletoe) that penetrates the host's tissue and draws nutrients from it. In mycology, it refers to the appendage or portion of a parasitic fungus (the hyphal tip), which performs a similar function. Microscopic haustoria penetrate the host plant's cell wall and siphon nutrients from the space between the cell wall and plasma membrane but do not penetrate the membrane itself. Larger (usually botanical, not fungal) haustoria do this at the tissue level.Höðr
Höðr (Old Norse: Hǫðr [ˈhɔðr] (listen); often anglicized as Hod, Hoder, or Hodur) is a blind god and a son of Odin and Frigg in Norse mythology. Tricked and guided by Loki, he shot the mistletoe arrow which was to slay the otherwise invulnerable Baldr.
According to the Prose Edda and the Poetic Edda, the goddess Frigg, Baldr's mother, made everything in existence swear never to harm Baldr, except for the mistletoe, which she found too unimportant to ask (alternatively, which she found too young to demand an oath from). The gods amused themselves by trying weapons on Baldr and seeing them fail to do any harm. Loki, the mischief-maker, upon finding out about Baldr's one weakness, made a spear from mistletoe, and helped Höðr shoot it at Baldr. In reaction to this, Odin and the giantess Rindr gave birth to Váli, who grew to adulthood within a day and slew Höðr.
The Danish historian Saxo Grammaticus recorded an alternative version of this myth in his Gesta Danorum. In this version, the mortal hero Høtherus and the demi-god Balderus compete for the hand of Nanna. Ultimately, Høtherus slays Balderus.List of Casualty specials
Casualty is a British medical drama television series that premiered in the United Kingdom on BBC One on 6 September 1986. It is the longest-running emergency medical drama television series in the world, and the most enduring medical drama broadcast on primetime television in the world. Casualty is set in the fictional Holby City Hospital and focuses on the staff and patients of the hospital's emergency department (ED). The drama was created by Jeremy Brock and Paul Unwin, while Geraint Morris produced the first three series. The drama has aired for 32 series and a 33rd series currently airs. Over 1,000 episodes have aired in total. Holby City, a spin-off of Casualty, was commissioned in 1998 and began airing on 12 January 1999. The two shows are closely related with several crossover events occurring between them. Some crossovers broadcast between December 2004 and December 2005 are styled as episodes of Casualty@Holby City. A British police procedural drama and spin-off to Casualty, HolbyBlue was announced on 27 April 2006. It began on 8 May 2007 and was cancelled in August 2008 after 2 series and 20 episodes were broadcast.Casualty has produced 19 special episodes, including the first webisode commissioned for a BBC continuing drama. Belinda Campbell, who executively produced the drama between 2007 and 2011, thought that webisodes would be a "new [way] to add value for our loyal fans", something which the team constantly look to do. Casualty filmed a sketch for charity telethon Children in Need in 2009, featuring charity mascot Pudsey Bear. In 2010, cast members on the show filmed a tribute to BBC soap opera EastEnders and Blue Peter presenter Joel Defries presented a segment of the show from the Casualty set. To celebrate Casualty's thirtieth anniversary, original cast members Derek Thompson and Cathy Shipton filmed a special episode, "Back to Ours", showing moments from their careers on the show.
Webisodes have been created to explore characters in more detail: "The Parting of the Ways" focuses on Alistair (Joe McFadden); "Under Fire" details Sam Nicholls' (Charlotte Salt) backstory; and "Scars and Nightmares" explores the backstory of Iain Dean (Michael Stevenson). Other webisodes are designed to help progress storylines on the main show: "Short Story" explores Ruth Winters' (Georgia Taylor) stay at the hospital's psychiatric ward; "Mistletoe and Rum" follows the secret relationship between Tess Bateman (Suzanne Packer) and Adrian "Fletch" Fletcher (Alex Walkinshaw); "Nurse Factor" supports the introduction of four new student nurse characters; "Gone in Sixty Seconds" gives an insight into a bus crash; "Mrs Walker-To-Be" explores the night before Zoe Hanna (Sunetra Sarker) and Max Walker's (Jamie Davis) wedding; and "On Call" starts a storyline featuring Caleb Knight (Richard Winsor) being told he has a daughter. Some webisodes have been standalone and not followed in the main show: "The Kids Aren't Alright" focuses on Jeff Collier's (Matt Bardock) estrangement from his children; "The Spirit of Christmas" and "The First Noel" are Christmas specials; and "Radio Holby" sees Noel Garcia (Tony Marshall) become the hospital's radio DJ.Mistle thrush
The mistle thrush (Turdus viscivorus) is a bird common to much of Europe, Asia and North Africa. It is a year-round resident in a large part of its range, but northern and eastern populations migrate south for the winter, often in small flocks. It is a large thrush with pale grey-brown upper parts, a greyish-white chin and throat, and black spots on its pale yellow and off-white under parts. The sexes are similar in plumage, and its three subspecies show only minimal differences. The male has a loud, far-carrying song which is delivered even in wet and windy weather, earning the bird the old name of stormcock.
Found in open woods, parks, hedges and cultivated land, the mistle thrush feeds on a wide variety of invertebrates, seeds and berries. Its preferred fruits include those of the mistletoe, holly and yew. Mistletoe is favoured where it is available, and this is reflected in the thrush's English and scientific names; the plant, a parasitic species, benefits from its seeds being excreted by the thrush onto branches where they can germinate. In winter, a mistle thrush will vigorously defend mistletoe clumps or a holly tree as a food reserve for when times are hard.
The open cup nest is built against a trunk or in a forked branch, and is fearlessly defended against potential predators, sometimes including humans or cats. The clutch, typically of three to five eggs, is incubated for 12–15 days, mainly by the female. The chicks fledge about 14–16 days after hatching. There are normally two broods. There was a large range expansion in the 18th and early 19th centuries, and a small decline in recent decades, perhaps due to changes in agricultural practices. Given its high numbers and very large range, this thrush is classified by the International Union for Conservation of Nature as being of least concern.Mistletoe (Justin Bieber song)
"Mistletoe" is a Christmas song by Canadian singer Justin Bieber. It was written and produced by Nasri, and Adam Messinger. The song was released on October 17, 2011 as the lead single from his Christmas album, Under the Mistletoe (2011). "Mistletoe" is a pop and R&B song, that has reggae influences. "Mistletoe" received generally positive reviews from most music critics. The song reached the top ten in Canada, Denmark and Norway, and slightly missed the top 10 in the US, peaking at 11, while also reaching the top forty in nine other countries. The song's accompanying music video was directed by Roman White. It features the singer singing on a snowy, lit-up street. It also Justin Bieber’s only song to be released in 2011.Mistletoe (album)
Mistletoe is a comedy album by The Bob & Tom Show, which was first released in December 2003. It is a single disc CD which represents original material recorded during their syndicated, daily radio show and other studio numbers which had not been previously presented on air.Mistletoe State Park
Mistletoe State Park is a 1,972 acre (7.98 km²) Georgia state park located northwest of Augusta, Georgia on the southern shore of Lake Strom Thurmond. The park gets its name from Mistletoe Corners, a local area where people gather to pick mistletoe during the winter holiday season. Its strategic location on the lake makes it one of the finest bass fishing spots in the nation. The park also offers public beaches and 8 miles of nature trails.Mistletoe and Wine
"Mistletoe and Wine" is a Christmas song made famous as a single by Cliff Richard in 1988.
The song was written by Jeremy Paul, Leslie Stewart and Keith Strachan for a musical called Scraps, which was an adaptation of Hans Christian Andersen's "The Little Match Girl" set in Victorian London.Mistletoebird
The mistletoebird (Dicaeum hirundinaceum), also known as the mistletoe flowerpecker, is a species of flowerpecker native to most of Australia (though absent from Tasmania and the driest desert areas) and also to the eastern Maluku Islands of Indonesia in the Arafura Sea between Australia and New Guinea. The mistletoebird eats mainly the berries of the parasitic mistletoe and is a vector for the spread of the mistletoe's seeds, through its digestive system.Phoradendron leucarpum
Phoradendron leucarpum is a species of mistletoe in the Viscaceae family which is native to the United States and Mexico. Its common names include American mistletoe, eastern mistletoe, hairy mistletoe and oak mistletoe. It is native to Mexico and the south eastern half of the continental US. It is hemiparasitic, living in the branches of trees. The berries are white and 3–6 millimeters (0.12–0.24 in). It has opposite leaves that are leathery and thick.
Ingesting the berries can cause "stomach and intestinal irritation with diarrhea, lowered blood pressure, and slow pulse". This shrub can grow to 1 meter (3.3 ft) by 1 meter (3.3 ft).Redding, California
Redding is a city in and the county seat of Shasta County, California, United States, in the northern part of the state. It lies along the Sacramento River, 162 miles (261 kilometers) north of Sacramento, and 120 miles (190 km) south of California's northern border, shared with the state of Oregon. Interstate 5 bisects the entire city, from the south to north before it approaches Shasta Lake, which is located 15 miles (24 km) to the north. The 2010 population was 89,861. Redding is the largest city in the Shasta Cascade region, and it is the sixth-largest city in the Sacramento Valley, behind Sacramento, Elk Grove, Roseville, Vacaville and Chico.Santalales
The Santalales are an order of flowering plants with a cosmopolitan distribution, but heavily concentrated in tropical and subtropical regions. It derives its name from its type genus Santalum (sandalwood). Mistletoe is the common name for a number of parasitic plants within the order.The Mistletoe Mystery
The Mistletoe Mystery is the 169th volume of the Nancy Drew Mystery Stories series.Under the Mistletoe
Under the Mistletoe is the first Christmas album and second studio album by Canadian recording artist Justin Bieber. It was released on November 1, 2011, by Island Records.Viscum album
Viscum album is a species of mistletoe in the family Santalaceae, commonly known as European mistletoe, common mistletoe or simply as mistletoe (Old English mistle). It is native to Europe and western and southern Asia.
Viscum album is a hemiparasite on several species of trees, from which it draws water and nutrients. It has a significant role in European mythology, legends, and customs. In modern times, it is commonly featured in Christmas decoration and symbology. (V. album is found only rarely in North America, as an introduced species; its cultural roles are usually fulfilled by the similar native species Phoradendron leucarpum.)