出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2014/04/07 17:42:27」(JST)
Galanthus | |
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Common snowdrop | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Asparagales |
Family: | Amaryllidaceae |
Subfamily: | Amaryllidoideae |
Genus: | Galanthus L. |
Species | |
See text |
Galanthus (Snowdrop; Greek gála "milk", ánthos "flower") is a small genus of about 20 species of bulbous herbaceous plants in the family Amaryllidaceae, subfamily Amaryllidoideae.[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 their relatives, snowflakes, which are Leucojum and Acis species.
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.[2] 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.[3]
Most other Galanthus species are from the eastern Mediterranean, though several are found in southern Russia, Georgia, Armenia and Azerbaijan.[4] Galanthus fosteri comes from Jordan, Lebanon, Syria, Turkey and maybe Israel.[5]
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.[6]
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.[7] 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.[8]
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. 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).[9] Several gardens in England open during snowdrop season for the National Gardens Scheme (NGS).
There are a number of snowdrop gardens in England, Wales, Scotland and Ireland.[10]
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.[11] 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:-
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A list of Irish cultivars can be found here [1]
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.
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.[21] 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.[22]
In 1995 Árpád Pusztai genetically modified potatoes with the GNA gene, which work he discussed on a radio interview in 1998[23] and published in the Lancet in 1999.[24] 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".[23] These remarks started the so-called Pusztai affair.
As of February 2012[update], the World Checklist of Selected Plant Families recognises 19 species:[25]A 20th species, Galanthus panjutinii (Panjutin's snowdrop), was recognised during 2012. Discovered in five locations in a small area (estimated at 20km2) of the northern Colchis area (western Transcaucasus) of Georgia and Russia, it is classed as Endangered. One of its five known sites, at Sochi, has been destroyed by preparations for the 2014 Winter Olympics.[26]
Notable species include:
Snowdrops are sometimes confused with their relatives, snowflakes, Leucojum and Acis species. Leucojums 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.
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(help)Wikimedia Commons has media related to Galanthus nivalis. |
リンク元 | 「snowdrop」「ガランツス属」 |
拡張検索 | 「Galanthus nivalis」「Galanthus属」 |
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