Galanthus


Galanthus is a small genus of approximately 20 species of bulbous perennial herbaceous plants in the family Amaryllidaceae. The plants have two linear leaves and a single small white drooping bell shaped flower with six petal-like tepals in two circles. The smaller inner petals have green markings.
Snowdrops have been known since the earliest times under various names, but were named Galanthus in 1753. As the number of recognised species increased, various attempts were made to divide the species into subgroups, usually on the basis of the pattern of the emerging leaves. In the era of molecular phylogenetics this characteristic has been shown to be unreliable and now seven molecularly defined clades are recognised that correspond to the biogeographical distribution of species. New species continue to be discovered.
Most species flower in winter, before the vernal equinox, but some flower in early spring and late autumn. Sometimes snowdrops are confused with the two related genera within the tribe Galantheae, snowflakes Leucojum and Acis.

Description

General

All species of Galanthus are perennial petaloid herbaceous bulbous monocot plants. The genus is characterised by the presence of two leaves, :wikt:pendulous|pendulous white flowers with six free perianth segments in two whorls. The inner whorl is smaller than the outer whorl and has green markings.

Vegetative

; Leaves:
These are basal, emerging from the bulb initially enclosed in a tubular membranous sheath of cataphylls. Generally, these are two in number and linear, strap-shaped, or oblanceolate. Vernation, the arrangement of the emerging leaves relative to each other, varies among species. These may 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. In the past, this feature has been used to distinguish between species and to determine the parentage of hybrids, but now has been shown to be homoplasious, and not useful in this regard.
The scape is erect, leafless, terete, or compressed.

Reproductive

;Inflorescence :
The scape bears at the top a pair of bract-like spathe valves usually fused down one side and joined by a papery membrane, appearing monophyllous. From between them emerges a solitary, pendulous, nodding, bell-shaped white flower, held on a slender pedicel. The flower bears six free perianth segments rather than petals, arranged in two whorls of three, the outer whorl being larger and more convex than the inner series. The outer tepals are acute to more or less obtuse, spathulate or oblanceolate to narrowly obovate or linear, shortly clawed, and erect spreading. The inner tepals are much shorter, oblong, spathulate or oblanceolate, somewhat :wikt:unguiculate|unguiculate and tapered to the base and erect. These tepals also bear green markings at the base, apex, or both, that when at the apex, are bridge-shaped over the small sinus at the tip of each tepal, which are emarginate. Occasionally the markings are either green-yellow, yellow, or absent, and the shape and size varies by species.
; Androecium :
The six stamens are inserted at the base of the perianth, and are very short, the anthers basifixed with filaments much shorter than the anthers and dehisce by terminal pores or short slits.
; Gynoecium, Fruit and Seeds:
The inferior ovary is three-celled. The style is slender and longer than the anthers, the stigma are minutely capitate. The ovary ripens into a three-celled capsule fruit. This fruit is fleshy, ellipsoid or almost spherical, opening by three flaps with seeds that are light brown to white and oblong with a small appendage or tail containing substances attractive to ants, which distribute the seeds.
The chromosome number is 2n=24.
Floral formula:

Distribution and habitat

The genus Galanthus is native to Europe and the Middle East, from the Spanish and French Pyrenees in the west through to the Caucasus and Iran in the east, and south to Sicily, the Peloponnese, the Aegean, Turkey, Lebanon, and Syria. The northern limit is uncertain because G. nivalis has been widely introduced and cultivated throughout Europe. G. nivalis and some other species valued as ornamentals have become widely naturalised in Europe, North America, and other regions.
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. 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 probably was introduced around the early sixteenth century and is currently not a protected species in the UK. It was first recorded as naturalised in the UK in Worcestershire and Gloucestershire in 1770. Most other Galanthus species are from the eastern Mediterranean, but several are found in southern Russia, Georgia, Armenia, and Azerbaijan. Galanthus fosteri comes from Jordan, Lebanon, Syria, Turkey, and perhaps, Palestine.
Galanthus grows best in woodland, in acid or alkaline soil, although some are grassland or mountain species.

Taxonomy

History

Early

Snowdrops have been known since early times, being described by the classical Greek author, Theophrastus, in the fourth century BC in his, Περὶ φυτῶν ἱστορία. He gave it, and similar plants, the name λευκόἲον from which the later name Leucojum was derived. He described the plant as "ἑπεἰ τοῖς γε χρώμασι λευκἂ καἱ οὐ λεπυριώδη" and of their habits "Ἰῶν δ' ἁνθῶν τὀ μἑν πρῶτον ἑκφαἱνεται τὁ λευκόἲον, ὅπου μἑν ό ἀἠρ μαλακώτερος εὐθὑς τοῦ χειμῶνος, ὅπου δἐ σκληρότερος ὕστερον, ἑνιαχοῡ τοῡ ἣρος"
Rembert Dodoens, a Flemish botanist, had described and illustrated this plant in 1583 as did Gerard in England in 1597, calling it, Leucojum bulbosum praecox. Gerard refers to Theophrastus' description as Viola alba or Viola bulbosa using Pliny's translation, and comments that the plant had originated in Italy and had "taken possession" in England "many years past". The genus was formally named Galanthus and described by Carl Linnaeus in 1753, with the single species, Galanthus nivalis, which is the type species. Consequently, Linnaeus is granted the botanical authority. In doing so, he distinguished this genus and species from Leucojum, a name by which it previously had been known.

Modern

In 1763 Adanson began a system of arranging genera in families. Using the synonym Acrocorion, he placed Galanthus in the family Liliaceae, section Narcissi. Lamarck provided a description of the genus in his encyclopedia, and later, Illustrations des genres. In 1789 de Jussieu, who is credited with the modern concept of genera organised in families, placed Galanthus and related genera within a division of Monocotyledons, using a modified form of Linnaeus' sexual classification, but with the respective topography of stamens to carpels rather than just their numbers. In doing so he restored the name Galanthus and retained their placement under Narcissi, this time as a family and referred to the French vernacular name, :fr:Perce-neige|Perce-neige, based on the plants tendency to push through early spring snow ]. The modern family of Amaryllidaceae, in which Galanthus is placed, dates to Jaume Saint-Hilaire who replaced Jussieu's Narcissi with Amaryllidées. In 1810 Brown proposed that a subgroup of Liliaceae be distinguished on the basis of the position of the ovaries and be referred to as Amaryllideae, and in 1813, de Candolle separated them by describing Liliacées Juss. and Amaryllidées Brown as two quite separate families. However, in his comprehensive survey of the Flora of France he divided Liliaceae into a series of Ordres, and placed Galanthus into the Narcissi Ordre. This relationship of Galanthus to either liliaceous or amaryllidaceaous taxa was to last for another two centuries until the two were formally divided at the end of the twentieth century. Lindley followed this general pattern, placing Galanthus and related genera such as Amaryllis and Narcissus in his Amaryllideae. By 1853, the number of known plants was increasing considerably and he revised his schema in his last work, placing Galanthus together, and the other two genera in the modern Galantheae in tribe Amarylleae, order Amaryllidaceae, alliance Narcissales. These three genera have been treated together taxonomically by most authors, on the basis of an inferior ovary. As the number of plant species increased, so did the taxonomic complexity. By the time Bentham and Hooker published their Genera plantarum ordo Amaryllideae contained five tribes, and tribe Amarylleae 3 subtribes. They placed Galanthus in subtribe Genuinae and included three species.

Phylogeny

Galanthus is one of three closely related genera making up the tribe Galantheae within subfamily Amaryllidoideae. Sometimes snowdrops are confused with the other two genera, Leucojum and Acis. Leucojum species are much larger and flower in spring, with all six tepals in the flower being the same size, although some "poculiform" Galanthus species may have inner segments similar in shape and length to the outer ones. Galantheae are likely to have arisen in the Caucusus.

Subdivision

Galanthus has approximately 20 species, but new species continue to be described. G. trojanus was identified in Turkey in 2001. G. panjutinii was discovered in 2012 in five locations in a small area of the northern Colchis area of Georgia and Russia. G. samothracicus was identified in Greece in 2014. Since it has not been subjected to genetic sequencing, it remains unplaced. It resembles G. nivalis, but is outside the distribution of that species.
Many species are difficult to identify, however, and traditional infrageneric classification based on morphological alone, such as those of Stern, Traub and Davis, has not reflected what is known about its evolutionary history due to the morphological similarities among the species, and relative lack of easily discernible distinguishing characteristics. Stern divided the genus into three series according to leaf vernation ;
Stern further utilised characteristics such as the markings of the inner segments, length of the pedicels in relation to the spathe, and the colour and shape of the leaves in identifying and classifying species
Traub considered them as subgenera;
By contrast Davis, with much more information and specimens, included biogeography in addition to vernation, forming two series. He used somewhat different terminology for vernation, namely applanate, explicative, and supervolute. He merged Nivalis and Plicati into series Galanthus, and divided Latifolii into two subseries, Glaucaefolii A.P.Davis and Viridifolii A.P.Davis.
Early molecular phylogenetic studies confirmed the genus was monophyletic and suggested four clades, which were labelled as series, and showed that Davis' subseries were not monophyletic. An expanded study in 2013 demonstrated seven major clades corresponding to biogeographical distribution. This study used nuclear encoded nrITS, and plastid encoded matK, trnL-F, ndhF, and psbK–psbI, and examined all species recognised at the time, as well as two naturally occurring putative hybrids. The morphological characteristic of vernation that earlier authors had mainly relied on was shown to be highly homoplasious. A number of species, such as G. nivalis and G. elwesii demonstrated intraspecific biogeographical clades, indicating problems with speciation and there may be a need for recircumscription. These clades were assigned names, partly according to Davis' previous groupings. In this model clade Platyphyllus is sister to the rest of the genus.
By contrast another study performed at the same time, using both nuclear and chloroplast DNA, but limited to the 14 species found in Turkey, largely confirmed Davis' series and subseries, and with biogeographical correlation. Series Galanthus in this study corresponded to clade nivalis, subseries Glaucaefolii with clade Elwesii and subseries Viridifolii with clades Woronowii and Alpinus. However, the model did not provide complete resolution.

Clades

sensu Ronsted et al. 2013
;Selected species
Galanthus is derived from the Greek γάλα, meaning "milk" and ἄνθος meaning "flower", alluding to the colour of the flowers. The epithet nivalis is derived from the Latin, meaning "of the snow". The word "Snowdrop" may be derived from the German Schneetropfen, the tear drop shaped pearl earrings popular in the sixteenth and seventeenth centuries. Other, earlier, common names include Candlemas bells, Fair maids of February, and White ladies.

Ecology

Snowdrops are hardy herbaceous plants that perennate by underground bulbs. They are among the earliest spring bulbs to bloom, although a few forms of G. nivalis are autumn flowering. In colder climates, they will emerge through snow. They naturalise relatively easily forming large drifts. These are often sterile, found near human habitation, and also former monastic sites. The leaves die back a few weeks after the flowers have faded. Galanthus plants are relatively vigorous and may spread rapidly by forming bulb offsets. They also spread by dispersal of seed, animals disturbing bulbs, and water if disturbed by floods.

Conservation

Some snowdrop species are threatened in their wild habitats, due to habitat destruction, illegal collecting, and climate change. In most countries collecting bulbs from the wild is now illegal. 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 lists all species, but allows a limited trade in wild-collected bulbs of just three species from Turkey and Georgia. A number of species are on the IUCN Red List of threatened species, with the conservation status being G. trojanus as critically endangered, four species vulnerable, G. nivalis is near threatened and several species show decreasing populations. G. panjutinii is considered endangered. One of its five known sites, at Sochi, was destroyed by preparations for the 2014 Winter Olympics.

Cultivation

Galanthus species and cultivars are extremely popular as symbols of spring and are traded more than any other wild-source ornamental bulb genus. Millions of bulbs are exported annually from Turkey and Georgia. For instance export quotas for 2016 for G. elwesii are 7 million for Turkey and 15 million for Georgia. Data for G. worononowii are 15 million for Georgia. These figures include both wild-taken and artificially propagated bulbs.

Snowdrop gardens

Celebrated as a sign of spring, snowdrops may 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. Several gardens open specially in February for visitors to admire the flowers. Sixty gardens took part in Scotland's first Snowdrop Festival. Several gardens in England open during snowdrop season for the National Gardens Scheme and in Scotland for Scotland's Gardens. Colesbourne Park in Gloucestershire is one of the best known of the English snowdrop gardens, being the home of Henry John Elwes, a collector of Galanthus specimens, and after whom Galanthus elwesii is named.

Cultivars

Numerous single- and double-flowered cultivars of Galanthus nivalis are known, and also of several other Galanthus species, particularly G. plicatus and G. elwesii. Also, many hybrids between these and other species exist. 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 snowdrop collectors, known as "galanthophiles", who hold meetings where the scarcer cultivars change hands. 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. Many hybrids have also occurred in cultivation.

Awards

In the UK the following have gained the Royal Horticultural Society's Award of Garden Merit:-
Propagation is by offset bulbs, either by careful division of clumps in full growth, 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.

Toxicity

Snowdrops contain an active lectin or agglutinin named GNA for Galanthus nivalis agglutinin.
In 1995, Árpád Pusztai genetically modified potatoes to express the GNA gene, which he discussed on a radio interview in 1998, and published in the Lancet in 1999. These remarks started the so-called Pusztai affair. This early research caused the GNA to be found in the edible part of the plant, i.e. in the potato.
Using improved techniques, 22 years later, in 2017, a research team at the Gansu Agricultural University, Lanzhou, China created another transgenic potato plant. These plants produce potatoes that do not contain any GNA. These plants express GNA in their leaves, stems, and roots. They show a reduction in the number of potato aphids and peach-potato aphids per plant of up to 50%.

Medicinal use

In 1983, Andreas Plaitakis and Roger Duvoisin suggested that the mysterious magical herb, moly, that appears in Homer's Odyssey is the snowdrop. An active substance in snowdrop is called galantamine, which, as an acetylcholinesterase inhibitor, could have acted as an antidote to Circe's poisons. Further supporting this notion are notes made during the fourth century BC by the Greek scholar Theophrastus who wrote in Historia plantarum that moly was "used as an antidote against poisons" although which specific poisons it was effective against remains unclear. Galantamine may be helpful in the treatment of Alzheimer's disease, although it is not a cure; the substance also occurs naturally in daffodils and other narcissi.

In popular culture

Snowdrops figure prominently in art and literature, often as a symbol in poetry of spring, purity, and religion, such as Walter de la Mare's poem The Snowdrop. In this poem, he likened the triple tepals in each whorl to the Holy Trinity. He used snowdrop imagery several times in his poetry, such as Blow, Northern Wind – see Box. Another instance is the poem by Letitia Elizabeth Landon in which she asks "Thou fairy gift from summer, Why art thou blooming now?"
Early names refer to the association with the religious feast of Candlemas the optimum flowering time in which white-robed young women proceeded in the procession associated with the Purification, an alternative name for the feast day. The French name of Violette de la Chandaleur refers to Candlemas, while an Italian name, Fiore della purificazone, refers to purification. The German name of :de:Schneeglöckchen|Schneeglöckchen also invokes the symbol of bells.
In the Language of flowers, the Snowdrop is synonymous with 'Hope', as it blooms in early springtime, just before the vernal equinox, and so, is seen as 'heralding' the new spring and new year.
In more recent times, the snowdrop was adopted as a symbol of sorrow and of hope following the Dunblane massacre in Scotland, and lent its name to the subsequent campaign to restrict the legal ownership of handguns in the UK.

Books

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