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''Roscoea alpina'' is a perennial herbaceous plant native to the Himalayas.〔 Most members of the ginger family (Zingiberaceae), to which it belongs, are tropical, but ''R. alpina'', like other species of ''Roscoea'', grows in much colder mountainous regions.〔 It is sometimes grown as an ornamental plant in gardens.〔 ==Description== ''Roscoea alpina'' is a perennial herbaceous plant. Like all members of the genus ''Roscoea'', it dies back each year to a short vertical rhizome, to which are attached the tuberous roots. When growth begins again, "pseudostems" are produced: structures which resemble stems but are actually formed from the tightly wrapped bases (sheaths) of its leaves.〔 ''R. alpina'' is one of the smaller members of the genus; plants are 10–20 cm tall, with four to six leaves. The first two or three leaves consist only of a sheath; the remaining two or three have in addition a smooth (glabrous) leaf blade, free from the pseudostem, 3–12 cm long by 1.2–2 cm wide. There is a very small ligule, extending to about 0.5 mm, at the junction of the leaf sheath and blade. The leaf blades taper to a point.〔 In its native habitats, ''R. alpina'' flowers between May and August. The stem (peduncle) of the flower spike is hidden by the leaf sheaths. At the base of the flower spike there is a small bract, 3–10 mm long. Flowers open in succession and are purple or lilac in colour.〔 Each flower has the typical structure for ''Roscoea'' (see the diagrams in that article). There is a tube-shaped outer calyx, 4–5 cm long with a two-lobed apex. Next the three petals (the corolla) form a tube which is longer than the calyx and terminates in three lobes, an upright more-or-less circular central lobe, about 1.5 cm in diameter (which forms a hood over the rest of the flower〔), and two more elongated side lobes. Inside the petals are structures formed from four sterile stamens (staminodes): two lateral staminodes form what appear to be upright petals, smaller than the corolla lobes; two central staminodes are fused to form a lip or labellum, about 1.5 cm long, which is divided at the end into two lobes.〔〔 The single functional stamen has a white or cream anther, about 5–6 mm long, with 1.5–2 mm long spurs formed from the connective tissue between the two capsules of the anther. The ovary expands to a 2.5–3.5 cm long capsule when seed is set.〔 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「Roscoea alpina」の詳細全文を読む スポンサード リンク
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