Viscum

Mistletoe (Viscum album)

The mistletoes of the genus Viscum is a genus of flowering plants in the family Sandelholzgewächse ( Santalaceae ). It is usual, however, afford just satisfaction to the more than three dozen Viscum species and their related genera such as Arceuthobium and Korthalsella the rank of a separate family of authentics mistletoe plants ( Viscaceae ). There are also, especially in the tropics and subtropics, the species still much richer family of belt flower plants ( Loranthaceae ), whose members also have the gehölzparasitischen life form type " Mistletoe ".

Etymology

The Latin genus Viscum is identical with the Latin word viscum for " glue ". Of the Romans was prepared from the sticky berries bird-lime, which was used to catch birds. The term viscosity ( measure of viscosity ) goes on late Latin viscosus "sticky" back and thus also on viscum, the sticky mucus of mistletoe berries ( Mistelleim ).

Description

Mistletoes are either evergreen or deciduous (eg Loranthus ) one - half or dioecious parasites that grow on trees or bushes. Its branches branch out often forked. Leaves appear in pairs or in whorls. In some species, in addition to water and their nutrients mainly relate of their hosts, the green, capable of photosynthesis parts (leaves, green branches) are very small. Species that grow on succulent hosts and so must bear with their hosts seasonal water shortages are even succulent. In extreme cases (with Viscum minimum) is located with the exception of flowers, the whole plant within the host. This is therefore a full parasite.

The male or female flowers of Viscum species are inconspicuous, 1-3 mm in diameter and greenish yellow. After pollination by insects and then been fertilized arise white, yellow or red berry fruits. In them, each individual seed.

A special feature of mistletoe fruits and seeds is that no seed coat is formed. Instead, the mesocarp forms a tacky layer formed of a substance which is called viscin. The viscin has two functions in the seed dispersal: A component is slippery, so that the seeds schleimumhüllten quickly pass through the digestive tract of birds. Second, the viscin is very sticky and glue the seeds on the branches of host trees firmly. Birds are spreading these seeds, either by eating only the pulp and wipe the sticky seeds on adjacent branches or eat the whole fruits and excrete the undigested seeds elsewhere again.

When germination occurs under the tiny seed leaves a "tube" with a terminal disc from which evolved on contact with a suitable host to yet smooth bark a haustorium, through which the seedling can penetrate into the channels of the host plant.

Dissemination

Mistletoes are common in the tropical, subtropical and temperate zones worldwide. The number of its recognized species is controversial and, depending on family delimitation between 400 and over 1400.

Cultural history and popular culture

Kissing under mistletoe hung in homes is one of the Christmas customs in the U.S. and England. The origin of the custom is not known.

Similarly, the mistletoe is a symbolic meaning in Germanic mythology. The god Loki kill Balder, the son of Odin and Frigg, by spanning the blind Hödr a mistletoe on the sheet and can aim at him. Mistletoes are Balder's "Achilles heel", since all the other elements of the earth have sworn the beautiful young god nothing to do any harm.

Mistletoes are in the Asterix comic books, a part of the brewed by the druid Getafix potion. Only the mistletoe give the potion and ultimately the Gauls incredible powers in defense of the last not yet occupied by the Romans village. The authors are probably inspired by the report of the Roman Pliny, that the priests of the Gauls, the Druids, mistletoe and the tree on which they grew, revered as sacred, especially when the mistletoe grew on an oak. Pliny describes the mistletoe were cut in a special ceremony by a white-robed Druids with a golden sickle and were then placed in a potion that would make barren animals fruitful and cure poisoning.

Folk names of mistletoe are thunder broom, Druidenfuß, witches broom, witches herb, wintergreen, goat butter, Albranken, Bird herb or wood cross.

In alternative medicine, mistletoe is said to have an anticarcinogenic effect, although this seems doubtful given the current study situation.

Types (selection)

• Mistletoe (Viscum album L. ): a native of Europe, North Africa and Asia Plant.
• Viscum articulatum Burm. f: is found in South and Southeast Asia, China and Australia; also grows parasitically on the parasite Dendrophthoe.
• Viscum capitellatum Sm: grows parasitically on the parasite Viscum Loranthus well as on other species.
• Viscum coloratum ( Kom ) Nakai: formerly been regarded as a subspecies of Weißbeerigen mistletoe species in East Asia (China, Korea, Japan and the Russian Far East ).
• Viscum crassulae Eckl. & Zeyh. Succulent species that grows on succulent Crassula.
• Red and rather habanero mistletoe ( Viscum cruciatum Sieber ex Boiss. ): In southern Spain as well, disjunct, endemic in Palestine.
• Viscum cuneifolium Baker: Madagascar endemic species
• Viscum loranthi Elmer: occurs in India, Nepal, Indonesia, the Philippines and China ( Yunnan ) and grows parasitically on the parasite Scurrula.
• Dwarf mistletoe ( Viscum minimum Harv. ): Succulent, almost entirely parasitic and is the smallest Mistelart.
• Viscum monoicum Roxb. ex DC. comes in India, Bangladesh, Bhutan, Sikkim, Myanmar, Sri Lanka, Thailand, Vietnam and China before (Guangxi, Yunnan ) and is often infested with parasites from their own seedlings.
• Viscum orientale Willd. Widespread in Asia Art
• . Viscum ovalifolium DC: occurs in India, Bhutan, Indonesia, Malaysia, Cambodia, Laos, Myanmar, Thailand, Vietnam, China and the Philippines; quite large sized species
• Viscum rotundifolium L. f: occurs in South Africa.
• Viscum triflorum DC:. African species that grows on many different hosts.