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''Potamogeton lucens'', or shining pondweed,〔 is an aquatic perennial plant native to Eurasia and North Africa. It grows in relatively deep, still or slow-flowing, calcareous freshwater habitats. ==Description== Shining pondweed is a large plant with robust creeping rhizomes and long, terete, branching stems, typically up to 2.5 m but exceptionally to 6 m. The leaves are large, 75–200 mm (exceptionally more) long and 25–65 mm wide, 2-6 times as long as broad;〔 as with the smaller ''P. gramineus'', the leaves on the branches are smaller than those on the main stem. The leaves are pale green or yellowish, translucent, shiny with distinctive netted veining, minutely denticulate margins, and a short petiole of 1–12 mm.〔 Floating leaves are absent. Flowers appear between June and September.〔 The fruits are 3 mm across. Like most other broad-leaved pondweeds, ''Potamogeton lucens'' is tetraploid, with 2n=52.〔 Over much of its range, shining pondweed is not likely to be confused with any other species. However, in southern Europe the related and quite similar ''P. schweinfurthii'' has recently been discovered.〔〔 ''P. lucens'' can usually be distinguished by its relatively broader leaves, 2-6 times as long as they are broad, and most or all of which are petiolate, but some forms are very difficult to distinguish without a detailed comparison of multiple characters.〔 However, there are hybrids with various other pondweed species including ''P. gramineus'' (''P.'' × ''angustifolius'' J.Presl.), ''P. perfoliatus'' (''P.'' × ''salicifolius'' Wolfg.), ''P. alpinus'' (''P.'' × ''nerviger'' Wolfg.), ''P. nodosus'' (''P.'' × ''subrufus'' Hagstr.) ''P. sarmaticus'' (''P.'' × ''pseudosarmaticus'' Papch.), ''P. crispus'' (''P.'' × ''cadburyae'' Dandy & G.Taylor), ''P. praelongus'' (''P''. × ''jutlandicus'' Zalewska-Gał.) and ''P. natans'' (''P.'' × ''fluitans'' Roth).〔 It hybridises with ''P. wrightii'' (''P.'' × ''inbaensis'' Kadono)in Japan〔 and China.〔 Some of these hybrids can be quite common, and are not always easy to distinguish from ''P. lucens''.〔 A triple hybrid, ''P. gramineus'' × ''lucens'' × ''perfoliatus'' (''P''. × ''torssandrii'' (Tiselius) Dörfler), is also known. 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 lucens」の詳細全文を読む スポンサード リンク
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