ほそばうきみくり (細葉浮実栗) [Index] [Back] わが国の北海道および本州の岩手県と長野県、それにヨーロッパやシベリア、アラスカに分布しています。高山の湖沼や湿原の池沼に生える、沈水から浮葉性の水生多年草で、高さは８０センチほどになります。葉は水面に達すると浮葉状態となり、長さ２メートルに達し、徐々に細くなる線形で、先端は円みを帯びます。７月から８月ごろ、分枝しない花茎を水面に出し、腋生（葉腋から出る）または腋上生（小柄と花茎が合着）の２〜５個の雌性頭花と、２〜３個の雄性頭花を離れてつけます。果実は集合果で、個々の果実は紡錘形、水面に浮いた状態でつきます。  ミクリ科ミクリ属の多年草で、学名は Sparganium angustifolium。英名は Narrow-leaved bur-reed。  The Narrow-leaved bur-reed (Sparganium angustifolium) belongs to the family Sparganiaceae. It is a perennial herb that is distributed in Hokkaido, Iwate and Nagano prefectures of Honshu in Japan, as well as in Europe, Siberia and Alaska. It is a submerged to floating aquatic perennial that grows in alpine lakes and marshes, and can reach about 80 cm in height. When the leaves reach the surface of the water, they become floating, reach a length of 2 m, are linear and gradually become thinner, and the tips are rounded. From July to August, the unbranched flower stalks are exposed to the surface of the water, and 2 to 5 female axillary or superaxillary flower heads and 2 to 3 male flower heads are attached separately. The fruits are aggregate fruits, and each fruit is spindle-shaped and floats on the surface of the water.  岩手県八幡平市「八幡平」にて、2021年07月25日撮影。  Shu Suehiro shu@botanic.jp