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''Eriophorum angustifolium'', commonly known as common cottongrass or common cottonsedge, is a species of sedge in the plant genus ''Eriophorum'' of the family Cyperaceae. Native to North America, North Asia, and Northern Europe, it is often found on peat or acidic soils, in open wetland, heath or moorland. It begins to flower in April or May and, after fertilisation in early summer, the small, unremarkable brown and green flowers develop distinctive white bristle-like seed-heads that resemble tufts of cotton; combined with its ecological suitability to bog, these characteristics give rise to the plant's alternative name, bog cotton. ''Eriophorum angustifolium'' is a hardy, herbaceous, rhizomatous, perennial sedge, able to endure in a variety of environments in the temperate, subarctic and arctic regions of Earth. Unlike ''Gossypium'', the genus from which cotton is derived, the bristles which grow on ''E. angustifolium'' are unsuited to textile manufacturing. Nevertheless, in Northern Europe, they were used as a substitute in the production of paper, pillows, candle-wicks, and wound-dressings. The indigenous peoples of North America use the plant in cooking and in the treatment of digestive problems. Following a vote in 2002, Plantlife International designated ''E. angustifolium'' the County Flower of Greater Manchester, as part of its British County Flowers campaign. ==Description== In the wild, ''Eriophorum angustifolium'' is a creeping rhizomatous perennial sedge, with an abundance of unbranched, translucent pink roots. Fully grown, it has a tall, erect stem shaped like a narrow cylinder or triangular prism; it is smooth in texture and green in colour. Reports of the plant's height vary; estimates include up to , ,〔Jermy ''et al.'', 2007〕 and up to .〔 ''E. angustifolium'' has "stiff grass-like foliage" consisting of long, narrow solidly dark green leaves, which have a single central groove, and narrow from their wide base to a rust-coloured triangular tip. Up to seven green and brown aerial peduncles and chaffs, roughly in size, protrude from umbels at the top of the stem from which achenes are produced after fertilisation, each with a single pappus; these combine to form a distinctive white perianth around long. ''Eriophorum angustifolium'' is described as "a rather dull plant" in winter and spring, but "simply breathtaking" in summer and autumn, when 1–7 conspicuous inflorescences – composed of hundreds of white pappi comparable to cotton, hair, tassels, and/or bristles – stand out against naturally drab surroundings. ''Eriophorum angustifolium'' differs from other species within the genus ''Eriophorum'' in its habitat and morphology.〔 Its multiple flower heads and growth from rhizomes distinguish it from ''E. vaginatum'', which has a single flower head and grows from dense tussocks.〔 Although ''E. latifolium'' has 2–12 flower heads, it has laxly caespitose (tufted) growth, and its pappi are forked.〔 The smooth peduncles and preference for acidic soil pH distinguishes ''E. angustifolium'' from ''E. gracile'', which grows in swamp with a neutral pH and has scabrid (rough) peduncles.〔 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「Eriophorum angustifolium」の詳細全文を読む スポンサード リンク
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