Galanthus
Galanthus + ), or snowdrop, 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, 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 :At the top of the scape is a pair of bract-like spathes usually fused down one side and joined by a papery membrane, appearing monophyllous. From between the spathes emerges a solitary, pendulous, nodding, bell-shaped white flower, held on a slender pedicel. The flower bears six free perianth segments rather than true petals, arranged in two whorls of three, the outer whorl being larger and more convex than the inner whorl. 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 unguiculate ; tapering to the base and erect. These tepals also bear green markings at the base, the 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; they 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 is 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. In the Udmurt republic of Russia, Galanthus are found even above the 56th parallel.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 most likely 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, while several are found in the Caucasus, in southern Russia, Georgia, Armenia, and Azerbaijan. Galanthus fosteri is found in Jordan, Lebanon, Syria, Turkey, and, perhaps, Palestine.
Most Galanthus species grow 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 BCE, 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, described and illustrated this plant in 1583 as did Gerard in England in 1597, calling it Leucojum bulbosum praecox. Gerard refers to Theophrastus's 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.