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''Galanthus'' (snowdrop; Greek ''gála'' "milk", ''ánthos'' "flower") is a small genus of about 20 species of bulbous herbaceous perennials in the Amaryllis family.〔(【引用サイトリンク】year=2001 onwards )〕 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.〔Bishop, Davis & Grimshaw (2002), p. 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.〔Bishop, Davis & Grimshaw (2002), pp. 1–2.〕 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〔Bishop, Davis & Grimshaw (2002), p. 17.〕 * 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''. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Galanthus」の詳細全文を読む スポンサード リンク
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