Galanthus

Revision as of 18:32, 16 November 2015 by Kiran Singh (talk | contribs) (Created page with "__NOTOC__ {{SI}} {{CMG}} ==Overview== '''''Galanthus''''' ('''snowdrop'''; Greek ''gála'' "milk", ''ánthos'' "flower") is a small genus of about 20 species of bul...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

WikiDoc Resources for Galanthus

Articles

Most recent articles on Galanthus

Most cited articles on Galanthus

Review articles on Galanthus

Articles on Galanthus in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Galanthus

Images of Galanthus

Photos of Galanthus

Podcasts & MP3s on Galanthus

Videos on Galanthus

Evidence Based Medicine

Cochrane Collaboration on Galanthus

Bandolier on Galanthus

TRIP on Galanthus

Clinical Trials

Ongoing Trials on Galanthus at Clinical Trials.gov

Trial results on Galanthus

Clinical Trials on Galanthus at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Galanthus

NICE Guidance on Galanthus

NHS PRODIGY Guidance

FDA on Galanthus

CDC on Galanthus

Books

Books on Galanthus

News

Galanthus in the news

Be alerted to news on Galanthus

News trends on Galanthus

Commentary

Blogs on Galanthus

Definitions

Definitions of Galanthus

Patient Resources / Community

Patient resources on Galanthus

Discussion groups on Galanthus

Patient Handouts on Galanthus

Directions to Hospitals Treating Galanthus

Risk calculators and risk factors for Galanthus

Healthcare Provider Resources

Symptoms of Galanthus

Causes & Risk Factors for Galanthus

Diagnostic studies for Galanthus

Treatment of Galanthus

Continuing Medical Education (CME)

CME Programs on Galanthus

International

Galanthus en Espanol

Galanthus en Francais

Business

Galanthus in the Marketplace

Patents on Galanthus

Experimental / Informatics

List of terms related to Galanthus

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Galanthus (snowdrop; Greek gála "milk", ánthos "flower") is a small genus of about 20 species of bulbous herbaceous perennials in the Amaryllis family.[1] Most flower in winter, before the vernal equinox (20 or 21 March in the Northern Hemisphere), but certain species flower in early spring and late autumn.

Snowdrops are sometimes confused with the two related genera within Galantheae, snowflakes Leucojum and Acis.

Description

All species of Galanthus are perennial, herbaceous plants which grow from bulbs. Each bulb generally produces just two or three linear leaves and an erect, leafless scape (flowering stalk), which bears at the top a pair of bract-like spathe valves joined by a papery membrane. From between them emerges a solitary, pendulous, bell-shaped white flower, held on a slender pedicel. The flower has no petals: it consists of six tepals, the outer three being larger and more convex than the inner series. The six anthers open by pores or short slits. The ovary is three-celled, ripening into a three-celled capsule. Each whitish seed has a small, fleshy tail (elaiosome) containing substances attractive to ants which distribute the seeds.[2] The leaves die back a few weeks after the flowers have faded.

The inner flower segments are usually marked with a green, or greenish-yellow, bridge-shaped mark over the small "sinus" (notch) at the tip of each tepal.

An important feature which helps to distinguish between species (and to help to determine the parentage of hybrids) is their "vernation" (the arrangement of the emerging leaves relative to each other). This can be "applanate", "supervolute" or "explicative". In applanate vernation the two leaf blades are pressed flat to each other within the bud and as they emerge; explicative leaves are also pressed flat against each other, but the edges of the leaves are folded back or sometimes rolled; in supervolute plants one leaf is tightly clasped around the other within the bud and generally remains at the point where the leaves emerge from the soil.[3]

Notable species include:

  • Common snowdrop, Galanthus nivalis, grows to around 7–15 cm tall, flowering between January and April in the northern temperate zone (January–May in the wild). Applanate vernation[4]
  • Crimean snowdrop, Galanthus plicatus, 30 cm tall, flowering January/March, white flowers, with broad leaves folded back at the edges (explicative vernation)
  • Giant snowdrop, Galanthus elwesii, a native of the Levant, 23 cm tall, flowering January/February, with large flowers, the three inner segments of which often have a much larger and more conspicuous green blotch (or blotches) than the more common kinds; supervolute vernation
  • Galanthus reginae-olgae, from Greece and Sicily, is quite similar in appearance to G. nivalis, but flowers in autumn before the leaves appear. The leaves, which appear in the spring, have a characteristic white stripe on their upper side; applanate vernation
    • G. reginae-olgae subsp. vernalis, from Sicily, northern Greece and the southern part of former Yugoslavia, blooms at the end of the winter with developed young leaves and is thus easily confused with G. nivalis.

Taxonomy

The genus was created by Carl Linnaeus in 1753, based on the type species Galanthus nivalis.[5] Galanthus is from the Greek gala, meaning "milk", and anthos, meaning "flower", alluding to the colour of the flowers. The epithet nivalis means "of the snow".[6]

Similar genera

Snowdrops are sometimes confused with the two related genera that constitute the Galantheae, snowflakes or Leucojum and Acis . Leucojum are much larger and flower in spring (or early summer, depending on the species), with all six tepals in the flower being the same size, though some "poculiform" (goblet- or cup-shaped) Galanthus can have inner segments similar in shape and length to the outer ones.

Species

As of February 2012, the World Checklist of Selected Plant Families recognises 19 species.[5] A 20th species, Galanthus panjutinii (Panjutin's snowdrop), was recognised during 2012. Discovered in five locations in a small area (estimated at 20 km2) of the northern Colchis area (western Transcaucasus) of Georgia and Russia, it is classed as Endangered. One of its five known sites, at Sochi, was destroyed by preparations for the 2014 Winter Olympics.[7]

Distribution and habitat

The genus Galanthus is native to Europe and the Middle East, from Spain, France and Germany in the west through to Iran in the east. It has become naturalized in other parts of Europe – Norway, Sweden, Great Britain, Belgium and the Netherlands – as well as in eastern Canada and the United States.[8]

Galanthus nivalis is the best-known and most widespread representative of the genus Galanthus. It is native to a large area of Europe, stretching from the Pyrenees in the west, through France and Germany to Poland in the north, Italy, Northern Greece, Bulgaria, Romania, Ukraine and European Turkey. It has been introduced and is widely naturalised elsewhere.[9] Although it is often thought of as a British native wild flower, or to have been brought to the British Isles by the Romans, it was probably introduced around the early sixteenth century and is currently not a protected species in the UK.[4]

Most other Galanthus species are from the eastern Mediterranean, though several are found in southern Russia, Georgia, Armenia and Azerbaijan.[10] Galanthus fosteri comes from Jordan, Lebanon, Syria, Turkey and maybe Israel.[11]

Conservation

Some snowdrop species are threatened in their wild habitats, and in most countries it is now illegal to collect bulbs from the wild. Under CITES regulations, international trade in any quantity of Galanthus, whether bulbs, live plants or even dead ones, is illegal without a CITES permit. This applies to hybrids and named cultivars as well as species. CITES does, however, allow a limited trade in wild-collected bulbs of just three species (G. nivalis, G, elwesii and G. woronowii) from Turkey and Georgia.[12]

Cultivation

Snowdrop gardens

Celebrated as a sign of spring, snowdrops can form impressive carpets of white in areas where they are native or have been naturalised. These displays may attract large numbers of sightseers. There are a number of snowdrop gardens in England, Wales, Scotland and Ireland.[13] Several gardens open specially in February for visitors to admire the flowers. Sixty gardens took part in Scotland's first Snowdrop Festival (1 Feb–11 March 2007).[14] Several gardens in England open during snowdrop season for the National Gardens Scheme (NGS) and in Scotland for Scotland's Gardens.

Cultivars

There are numerous single- and double-flowered cultivars of Galanthus nivalis, and also of several other Galanthus species, particularly G. plicatus and G. elwesii. There are also many hybrids between these and other species (there are more than 500 cultivars described in Bishop, Davis & Grimshaw's book, plus lists of many cultivars that have now been lost, and others not seen by the authors). They differ particularly in the size, shape and markings of the flower, the period of flowering, and other characteristics, mainly of interest to the keen (even fanatical) snowdrop collectors, known as "galanthophiles", who hold meetings where the scarcer cultivars change hands.[15] Double-flowered cultivars and forms, such as the extremely common Galanthus nivalis f. pleniflorus 'Flore Pleno', may be less attractive to some people but they can have greater visual impact in a garden setting.

The following species and cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-

  • G. nivalis f. pleniflorus 'Flore Pleno'[21]
  • G. plicatus[22]
  • G. 'S. Arnott'[23]
  • G. woronowii[24]

A list of Irish cultivars can be found here [2]

Propagation

Propagation is by offset bulbs, either by careful division of clumps in full growth ("in the green"), or removed when the plants are dormant, immediately after the leaves have withered; or by seeds sown either when ripe, or in spring. Professional growers and keen amateurs also use such methods as "twin-scaling" to increase the stock of choice cultivars quickly.

Active substances

It was suggested by Andreas Plaitakis and Roger Duvoisin in 1983 that the mysterious magical herb moly that appears in Homer's Odyssey is actually snowdrop. An active substance in snowdrop is called galantamine, which, as anticholinesterase, could have acted as an antidote to Circe's poisons.[25] Galantamine (or galanthamine) can be helpful in the treatment of Alzheimer's disease, though it is not a cure;[citation needed] the substance also occurs naturally in daffodils and other narcissi.[citation needed]

Snowdrops contain also an active lectin or agglutinin named GNA for Galanthus nivalis agglutinin.[26]

In 1995 Árpád Pusztai genetically modified potatoes with the GNA gene, which work he discussed on a radio interview in 1998[27] and published in the Lancet in 1999.[28] In 1998 said in an interview on a World in Action programme that his group had observed damage to the intestines and immune systems of rats fed the genetically modified potatoes. He also said "If I had the choice I would certainly not eat it", and that "I find it's very unfair to use our fellow citizens as guinea pigs".[27] These remarks started the so-called Pusztai affair.

In popular culture

  • In the fairy-tale play The Twelve Months by Russian writer Samuil Marshak, a greedy queen decrees that a basket of gold coins shall be rewarded to anyone who can bring her galanthus flowers in the dead of winter. A young orphan Girl is sent out during a snow storm by her cruel stepmother and find the spirits of the 12 months of the year, who take pity on her and not only save her from freezing to death, but make it possible for her to gather the flowers even in winter. The Soviet traditionally animated film The Twelve Months (1956), Lenfilm film The Twelve Months (1972) and the anime film Twelve Months (1980) (Sekai meisaku dowa mori wa ikiteiru in Japan) are based on this fairy-tale play.
  • "Snowdrops" was the nickname that the British people gave during the Second World War to the military police of the United States Army (who were stationed in the UK preparatory to the invasion of the continent) because they wore a white helmet, gloves, gaiters, and Sam Browne belt against their olive drab uniform
  • The short story The Snowdrop by Hans Christian Andersen follows the fate of a snowdrop from a bulb striving towards the light to a picked flower placed in a book of poetry.
  • In Stardust, a glass snowdrop is given to Dunstan for a kiss by Una. It's later used to protect Tristan from the magic of Lamia.
  • In the musical Kiss Me, Kate by Cole Porter (1948) the character Lilli/Katherine is deeply pleased at receiving a pre-opening night performance bouquet of "pansies, snowdrops, and rosemary. Our wedding bouquet," from her ex, Fred/Patruchio. But--the bouquet was meant for the younger, ingenue lead, Lois/Bianca.

See also

References

  1. P. F. Stevens (2001 onwards). "Angiosperm Phylogeny Website: Asparagales: Amaryllidoideae". Check date values in: |year= (help)
  2. Bishop, Davis & Grimshaw (2002), p. 7.
  3. Bishop, Davis & Grimshaw (2002), pp. 1–2.
  4. 4.0 4.1 Bishop, Davis & Grimshaw (2002), p. 17.
  5. 5.0 5.1 "World Checklist of Selected Plant Families". The Board of Trustees of the Royal Botanic Gardens, Kew. Retrieved 2012-02-03., search for "Galanthus"
  6. Hyam, R. & Pankhurst, R.J. (1995). Plants and their names : a concise dictionary. Oxford: Oxford University Press. ISBN 978-0-19-866189-4. pp. 202, 342.
  7. "Kew website: Galanthus panjutinii (Panjutin's snowdrop)". Retrieved 8 February 2013.
  8. "Galanthus". World Checklist of Selected Plant Families. Royal Botanic Gardens, Kew. Retrieved 2014-05-18.
  9. Davis (1999), pp. 95–96.
  10. Bishop, Davis & Grimshaw (2002), pp. 17–57.
  11. Bishop, Davis & Grimshaw (2002), p. 40.
  12. Bishop, Davis & Grimshaw (2002), p. 341–343.
  13. "Great British Gardens: Snowdrops and Snowdrop Gardens 2007". Retrieved 11 March 2007.
  14. "VisitScotland.com: Snowdrop Festival". Archived from the original on 3 March 2007. Retrieved 11 March 2007.
  15. Bishop, Davis & Grimshaw (2002), p. 329
  16. "RHS Plant Selector - Galanthus 'Atkinsii'". Retrieved 20 June 2013.
  17. "RHS Plant Selector - Galanthus elwesii". Retrieved 20 June 2013.
  18. "RHS Plant Selector - Galanthus elwesii var. monostictus". Retrieved 20 June 2013.
  19. "RHS Plant Selector - Galanthus 'Magnet'". Retrieved 20 June 2013.
  20. "RHS Plant Selector - Galanthus nivalis". Retrieved 20 June 2013.
  21. "RHS Plant Selector - Galanthus nivalis f. pleniflorus 'Flore Pleno'". Retrieved 20 June 2013.
  22. "RHS Plant Selector - Galanthus plicatus". Retrieved 20 June 2013.
  23. "RHS Plant Selector - Galanthus 'S. Arnott'". Retrieved 20 June 2013.
  24. "RHS Plant Selector - Galanthus woronowii". Retrieved 20 June 2013.
  25. Andreas Plaitakis & Roger C. Duvoisin (1983). "Homer's moly identified as Galanthus nivalis L.: physiologic antidote to stramonium poisoning". Clinical Neuropharmacology. 6 (1): 1–6. doi:10.1097/00002826-198303000-00001. PMID 6342763.
  26. Hester G et al. (1995) Structure of mannose-specific snowdrop (Galanthus nivalis) lectin is representative of a new plant lectin family Nature Structural Biology 2, 472 - 479
  27. 27.0 27.1 "Árpád Pusztai: Biological Divide – James Randerson interviews biologist Árpád Pusztai". London: The Guardian. 15 January 2008. Retrieved 25 April 2010.
  28. Ewen SW, Pusztai A (October 1999). "Effect of diets containing genetically modified potatoes expressing Galanthus nivalis lectin on rat small intestine". Lancet. 354 (9187): 1353–4. doi:10.1016/S0140-6736(98)05860-7. PMID 10533866.

Bibliography

Further reading

External links

Template:Wikispecies