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''Potamogeton trichoides'' is a species of aquatic plant known by the common name hairlike pondweed, native to Europe and western Asia where it grows in calcareous, usually nutrient-rich standing or slow-flowing water. ==Description== Hairlike pondweed is an aquatic perennial that dies back each winter into a large number of asexually produced resting bodies called turions. There are no rhizomes. It produces slender, cylindrical or slightly compressed, branching stems usually less than a metre in length but occasionally up to 2 m.〔 The submerged leaves are long and very narrow, typically 16–80 mm long and 0.3–1 mm wide, with the midrib occupying up to 70% of the width of the leaf near the base.〔 They are rigid and green turning darker with age. There are no floating leaves.〔 The inflorescence is a short spike of 3-5 flowers arising from the water on a slender peduncle. This species readily hybridizes with several other species of ''Potamogeton'' including ''P. berchtoldii'' (''P.'' × ''franconicus'' G.Fisch.), ''P. pusillus'' (''P.'' × ''grovesii'' Dandy & G.Taylor) and ''P. compressus'' (''P.'' × ''ripoides'' Baagøe).〔〔 Hairlike pondweed is diploid, with 2n=26 chromosomes.〔 Hairlike pondweed is one of the more distinctive fine-leaved pondweeds due to the characteristically stiff leaves dominated by the midrib and open but tightly rolled stipules. However, it tends to be rarer than other fine-leaved species and often grows in mixed beds with other fine-leaved water plants such as ''P. pusillus'' and ''Zannichellia palustris'', so it may be overlooked. 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「Potamogeton trichoides」の詳細全文を読む スポンサード リンク
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