Waterweed - Daytime mat

A floating perennial plant of the Potamogetonaceae (APG classification: Potamogetonaceae). It is similar to Potamogeton but larger. The submerged leaves are yellowish brown, with no distinction between petiole and blade, and have degenerated into string-like or wire-like leaves. It is found in many lakes and marshes in northern Japan, and is widely distributed in the cool temperate zone of the Northern Hemisphere.

[Otaki Sueo October 19, 2018]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

ヒルムシロ科（APG分類：ヒルムシロ科）の浮葉性多年草。ヒルムシロに似るが、より大形。水中葉は黄褐色、葉柄と葉身との別がなく、ひも状または針金状に退化している。北日本の湖沼に多く、北半球の冷温帯に広く分布。

［大滝末男　2018年10月19日］

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