Viscum album is a species of mistletoe

Mistletoe

Mistletoe is the common name for obligate hemi-parasitic plants in several families in the order Santalales. The plants in question grow attached to and within the branches of a tree or shrub.-Mistletoe in the genus Viscum:...

, the species originally so-named, and also known as European Mistletoe or Common Mistletoe to distinguish it from other related species. It is native to Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and western and southern Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

.

Witches' Broom looks similar but is an abnormal growth of the tree.

Description

It is a hemi-parasitic

Parasitic plant

A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in approximately 19 families of flowering plants are known. Parasitic plants have a modified root, the haustorium, that penetrates the host plant and connects to the xylem, phloem, or...

 shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

, which grows on the stems of other trees. It has stems 30–100 cm (11.8–39.4 in) long with dichotomous branching. The leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 are in opposite pairs, strap-shaped, entire, leathery textured, 2–8 cm (0.78740157480315–3.1 in) long , 0.8–2.5 cm (0.31496062992126–0.984251968503937 in) broad and are a yellowish-green in colour. This species is dioecious

Dioecious

Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...

 and the flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s are inconspicuous, yellowish-green, 2–3 mm (0.078740157480315–0.118110236220472 in) diameter. The fruit

Fruit

In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

 is a white or yellow berry

Berry

The botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....

 containing one (very rarely several) seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

 embedded in the very sticky, glutinous fruit pulp.

It is commonly found in the crowns of broad-leaved trees, particularly apple

Apple

The apple is the pomaceous fruit of the apple tree, species Malus domestica in the rose family . It is one of the most widely cultivated tree fruits, and the most widely known of the many members of genus Malus that are used by humans. Apple grow on small, deciduous trees that blossom in the spring...

, lime

Lime (fruit)

Lime is a term referring to a number of different citrus fruits, both species and hybrids, which are typically round, green to yellow in color, 3–6 cm in diameter, and containing sour and acidic pulp. Limes are a good source of vitamin C. Limes are often used to accent the flavors of foods and...

, hawthorn and poplar

Poplar

Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....

.

Classification

The mistletoe was one of the many species originally described by Linnaeus

Carolus Linnaeus

Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...

. Its species name is the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 adjective albus "white". It and the other members of the genus Viscum

Viscum

Viscum is a genus of about 70-100 species of mistletoes, native to temperate and tropical regions of Europe, Africa, Asia and Australasia. Traditionally, the genus has been placed in its own family Viscaceae, but recent genetic research by the Angiosperm Phylogeny Group shows this family to be...

were originally classified in the mistletoe family Viscaceae

Viscaceae

Viscaceae is a family of flowering plants. In past decades, several systems of plant taxonomy recognized this family, notably the 1981 Cronquist system...

, but this family has since been sunk into the larger family Santalaceae

Santalaceae

Santalaceae is a widely distributed family of flowering plants which, like other members of Santalales, are partially parasitic on other plants...

.

Subspecies

Several subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 are commonly accepted. They differ in fruit colour, leaf shape and size, and most obviously in the host trees utilised.

• Viscum album subsp. abietis (Wiesb.) Abromeit. Central Europe
  Central Europe
  Central Europe or alternatively Middle Europe is a region of the European continent lying between the variously defined areas of Eastern and Western Europe...
  
  . Fruit white; leaves up to 8 centimetres (3.1 in). On Abies
  Fir
  Firs are a genus of 48–55 species of evergreen conifers in the family Pinaceae. They are found through much of North and Central America, Europe, Asia, and North Africa, occurring in mountains over most of the range...
  
  .
• Viscum album subsp. album. Europe, southwest Asia
  Southwest Asia
  Western Asia, West Asia, Southwest Asia or Southwestern Asia are terms that describe the westernmost portion of Asia. The terms are partly coterminous with the Middle East, which describes a geographical position in relation to Western Europe rather than its location within Asia...
  
   east to Nepal
  Nepal
  Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
  
  . Fruit white; leaves 3–5 cm (1.2–2 in). On Malus
  Malus
  Malus , the apples, are a genus of about 30–35 species of small deciduous trees or shrubs in the family Rosaceae. Other studies go as far as 55 species including the domesticated Orchard Apple, or Table apple as it was formerly called...
  
  , Populus
  Poplar
  Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....
  
  , Tilia
  Tilia
  Tilia is a genus of about 30 species of trees native throughout most of the temperate Northern Hemisphere. The greatest species diversity is found in Asia, and the genus also occurs in Europe and eastern North America, but not western North America...
  
  , and less often on numerous other species, including (rarely) Quercus
  Oak
  An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
  
  .
• Viscum album subsp. austriacum (Wiesb.) Vollmann. Fruit yellow; leaves 2–4 cm (0.78740157480315–1.6 ). Central Europe. On Larix
  Larch
  Larches are conifers in the genus Larix, in the family Pinaceae. Growing from 15 to 50m tall, they are native to much of the cooler temperate northern hemisphere, on lowlands in the north and high on mountains further south...
  
  , Pinus
  Pine
  Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
  
  , Picea
  Spruce
  A spruce is a tree of the genus Picea , a genus of about 35 species of coniferous evergreen trees in the Family Pinaceae, found in the northern temperate and boreal regions of the earth. Spruces are large trees, from tall when mature, and can be distinguished by their whorled branches and conical...
  
  .
• Viscum album subsp. meridianum (Danser) D.G.Long. Southeastern Asia. Fruit yellow; leaves 3–5 cm (1.2–2 in). On Acer
  Maple
  Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...
  
  , Carpinus
  Hornbeam
  Hornbeams are relatively small hardwood trees in the genus Carpinus . Though some botanists grouped them with the hazels and hop-hornbeams in a segregate family, Corylaceae, modern botanists place the hornbeams in the birch subfamily Coryloideae...
  
  , Juglans
  Walnut
  Juglans is a plant genus of the family Juglandaceae, the seeds of which are known as walnuts. They are deciduous trees, 10–40 meters tall , with pinnate leaves 200–900 millimetres long , with 5–25 leaflets; the shoots have chambered pith, a character shared with the wingnuts , but not the hickories...
  
  , Prunus
  Prunus
  Prunus is a genus of trees and shrubs, which includes the plums, cherries, peaches, apricots and almonds. There are around 430 species spread throughout the northern temperate regions of the globe. Many members of the genus are widely cultivated for fruit and ornament.-Botany:Members of the genus...
  
  , Sorbus
  Sorbus
  Sorbus is a genus of about 100–200 species of trees and shrubs in the subfamily Maloideae of the Rose family Rosaceae. Species of Sorbus are commonly known as whitebeam, rowan, service tree, and mountain ash...
  
  .
• Viscum album subsp. creticum has recently been described from eastern Crete
  Crete
  Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...
  
  . Fruit white; leaves short. On Pinus brutia
  Turkish Pine
  Pinus brutia, the Turkish pine, is a pine native to the eastern Mediterranean region. The bulk of its range is in Turkey, but it also extends to the East Aegean Islands of Greece, the Crimea, Iran, Georgia, Azerbaijan, northern Iraq, western Syria, Lebanon, and Cyprus...
  
  .
• Viscum album subsp. coloratum Kom. is treated by the Flora of China as a distinct species Viscum coloratum (Kom) Nakai.

Cultural significance and uses

Mistletoe is an ingredient of pomace brandy

Pomace brandy

Pomace brandy is a liquor distilled from pomace. Examples include the Croatian / Montenegrin / Serbian lozovača , Cypriot zivania, French marc, Georgian chacha, German Tresterbrand, Greek tsipouro, Hungarian törköly, Italian grappa, Bulgarian grozdova, Portuguese aguardente, Romanian rachiu de...

 based liquor biska made in Istra

Istria

Istria , formerly Histria , is the largest peninsula in the Adriatic Sea. The peninsula is located at the head of the Adriatic between the Gulf of Trieste and the Bay of Kvarner...

, Croatia

Croatia

Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

.

Toxicity

The toxic lectin

Lectin

Lectins are sugar-binding proteins that are highly specific for their sugar moieties. They play a role in biological recognition phenomena involving cells and proteins. For example, some viruses use lectins to attach themselves to the cells of the host organism during infection...

 Viscumin has been isolated from Viscum album. Viscumin is a cytotoxic protein that binds to galactose

Galactose

Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....

 residues of cell surface glycoprotein

Glycoprotein

Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...

s and may be internalised by endocytosis

Endocytosis

Endocytosis is a process by which cells absorb molecules by engulfing them. It is used by all cells of the body because most substances important to them are large polar molecules that cannot pass through the hydrophobic plasma or cell membrane...

. Viscumin strongly inhibits protein synthesis by inactivating the 60 S ribosomal subunit.

Mythology and symbolism

Mistletoe has always attracted popular interest and has been surrounded by a number of myths and legends. In some countries it plays a part in Christmas

Christmas

Christmas or Christmas Day is an annual holiday generally celebrated on December 25 by billions of people around the world. It is a Christian feast that commemorates the birth of Jesus Christ, liturgically closing the Advent season and initiating the season of Christmastide, which lasts twelve days...

 festivities. Pliny

Pliny the Elder

Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

 recorded an ancient druid

Druid

A druid was a member of the priestly class in Britain, Ireland, and Gaul, and possibly other parts of Celtic western Europe, during the Iron Age....

ic belief that mistletoe collected from

Ritual of oak and mistletoe

The ritual of oak and mistletoe is described by Pliny the Elder, writing in the 1st century AD, as a religious ceremony in Gaul in which white-clad druids climbed a sacred oak, cut down the mistletoe growing on it, sacrificed two white bulls and used the mistletoe to cure infertility:Pliny was...

 oak

Oak

An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

s had special qualities; the same theme is reprised in the popular Asterix

Asterix

Asterix or The Adventures of Asterix is a series of French comic books written by René Goscinny and illustrated by Albert Uderzo . The series first appeared in French in the magazine Pilote on October 29, 1959...

comic books. In Norse myth, an arrow made of mistletoe was the only thing that was able to kill the god Balder

Balder

Baldr is a god in Norse mythology.In the 12th century, Danish accounts by Saxo Grammaticus and other Danish Latin chroniclers recorded a euhemerized account of his story...

. The goddess Frigg

Frigg

Frigg is a major goddess in Norse paganism, a subset of Germanic paganism. She is said to be the wife of Odin, and is the "foremost among the goddesses" and the queen of Asgard. Frigg appears primarily in Norse mythological stories as a wife and a mother. She is also described as having the power...

had asked all other things to vow not to hurt Balder, but she had ignored the mistletoe because it seemed too small to be dangerous.

General references

1. Flora of Pakistan: Viscum album
2. Viscum album subsp. creticum
3. Huxley, A., ed. (1992). New RHS Dictionary of Gardening 4: 676. ISBN 0-333-47494-5