Wednesday, 16 December 2009

Mistletoe




Christmas 2009


Each day from now until Christmas day one article will be devoted to a subject connected with Christmas. Today we take a look at Misletoe.

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Mistletoe is the common name for a group of hemi parasitic plants in the order Santanales that grow attached to and within the branches of a tree or shrub. Parasitism evolved only nine times in the plant kingdom; of those, the parasitic mistletoe habit has evolved independently five times: Misodendraceae, Loranthaceae, Santalaceae (formerly considered the separate family Eromelepidaceae), and Santalaceae (formerly treated as the separate family Viscaceae). Although Viscaceae and Eremolepidaceae were placed in a broadly-defined Santalaceae byAngiosperm PhylogenyGroup 2, DNA data indicates that they evolved independently.
The word 'mistletoe' is of uncertain etymology; it may be related to German Mist, for dung and Tang for branch, since mistletoe can be spread in the feces of birds moving from tree to tree. However, Old English mistel was also used for basil.
European mistletoe, Viscum album, is a poisonous plant that causes acute gastrointestinal problems including stomach pain, and diarrhea along with low pulse
The name was originally applied to Viscum album (European Mistletoe, Santalaceae), the only species native in Great Britain and much of Europe. Later the name was further extended to other related species, including Phoradendron serotinum (the Eastern Mistletoe of eastern North America, also Santalaceae). European Mistletoe is readily recognized by its smooth-edged oval evergreen leaves borne in pairs along the woody stem, and waxy white berries in dense clusters of 2 to 6. In America, the Eastern Mistletoe is similar, but has shorter, broader leaves and longer clusters of 10 or more berries. In theUnited States, Phoradendron flavescens is commercially harvested for Christmas decorations.
The largest family of Mistletoes, 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, (see picture right) and commonly reduce their growth but can kill them with heavy infestation. Viscum album can parasitise more than 200 tree and shrub species. Almost all mistletoes are hemi-parasites, bearing evergreen leaves that do some photosynthesis, and using the host mainly for water and mineral nutrients. However, the mistletoe first sprouts from bird feces on the trunk of the tree and indeed in its early stages of life takes it nutrients from this source. An exception is 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 The genus Arceuthobium (dwarf mistletoe; Santalaceae) has reduced photosynthesis; as an adult, it manufactures only a small proportion of the sugars it needs from its own photosythesis but as a seedling it actively photosynthesizes until a connection to the host is established.
Some species of the largest family, Loranthaceae, have small, insect-pollinated flowers
(as with Santalaceae), but others have spectacularly showy, large, bird-pollinated flowers.
Most mistletoe seeds are spread by birds, such as the Mistle Thrush
in Europe, the Phainopepla in southwestern North America, and Dicauem of Asia and Australia. However, distinguishing between this species and ones of other ecological biomes is not difficult. They derive sustenance and agility through eating the fruits and nuts (drupes). The seeds are excreted in their droppings and stick to twigs, or more commonly the bird grips the fruit in its bill, squeezes the sticky coated seed out to the side, and then wipes its bill clean on a suitable branch. The seeds are coated with a sticky material called viscin (containing both cellulosic strands and mucopolysaccharides), which hardens and attaches the seed firmly to its future host.

European mistletoe, Viscum album, figured prominently in Greek mythology, and is believed to be The Golden Bough of Aeneas, ancestor of the Romans The Norse god Baldr was killed with mistletoe.
Mistletoe bears fruit at the time of the Winter Solstice
, the birth of the new year, and may have been used in solstitial rites in Druidic Britain as a symbol of immortality. In Celtic mythology and in druid rituals, it was considered a remedy for barrenness in animals and an antidote to poison, although the fruits of many mistletoes are actually poisonous if ingested as they contain viscotoxins.
An old Christian tradition said that mistletoe was once a tree and furnished the wood of the Cross. After the Crucifixion, the plant shriveled and became dwarfed to a parasitic vine.
In Romanian traditions, mistletoe (vĂ¢sc in Romanian
) is considered a source of good fortune. The medical and the supposed magical properties of the plant are still used, especially in rural areas.
A popular myth says that mistletoe was cut with a gold
sickle and it lost its power if it fell and touched the ground. This is a confusion with the Holly 'holy' Tree, the most sacred tree of the druids (after the Oak) due to both plants being green all year, having colorful fruits and sharing similar history of winter months Getafix, the druid in the Asterix comics, was often seen up trees collecting mistletoe for his magic potion.
Mistletoe has sometimes been nicknamed the vampire
plant because it can probe beneath the tree bark to drain water and minerals, enabling it to survive during a drought. William Shakespeare gives it an unflattering reference in Titus Andronicus, Act II, Scene I: "Overcome with moss and baleful mistletoe".
Mistletoe is commonly used as a Christmas
decoration, though such use was rarely alluded to until the 18th century. Viscum album is used in Europe whereas Phoradendron serotinum is used in North America. According to custom, the mistletoe must not touch the ground between its cutting and its removal as the last of Christmas greens at Candlemas; it may remain hanging through the year, often to preserve the house from lightning or fire, until it was replaced the following Christmas Eve. The tradition has spread throughout the English-speaking world but is largely unknown in the rest of Europe. The appearance and nature of the fruit's content (viscin) is very similar to or suggestive of human semen and this has strengthened its pagan connections
Mistletoe (Phoradendron
flavescens) is the state floral emblem for the state of Oklahoma. The state did not have an official flower, leaving mistletoe as the assumed state flower until the Oklahoma Rose was designated as such in 2004.

According to a custom of Christmas cheer, any two people who meet under a hanging of mistletoe are obliged to kiss. The custom is of Scandinavian origin.[