やなぎたんぽぽ (柳蒲公英) [Index] [Back] わが国の各地をはじめ、台湾や朝鮮半島、それに北半球に広く分布しています。山地や海岸の日当たりの良い草地などに生え、高さは３０〜１２０センチになります。葉は長楕円状披針形で互生し、縁はまばらに鋸歯があるか全縁です。８月から９月ごろ、茎頂に直径２５〜３５ミリの黄色い頭花を咲かせます。頭花は両性の舌状花だけです。総苞は鐘形で、総苞片は３〜４列つきます。果実は黒褐色で円柱形の痩果で、冠毛がつきます。台湾華語では「繖花山柳菊」。  キク科ヤナギタンポポ属の多年草で、学名は Hieracium umbellatum (syn. Hieracium canadense)。英名は Canadian hawkweed。  The Canadian hawkweed (Hieracium umbellatum) belongs to Asteraceae (the Aster family). It is a perennial herb that is widely distributed throughout Japan, Taiwan, the Korean Peninsula, and the Northern Hemisphere. It grows in sunny grassland in mountainous areas and coastal areas, and grows 30 to 120 cm tall. The leaves are oblong-lanceolate and alternate, with sparsely serrate or entire margins. Yellow flower-heads, 25 to 35 mm in diameter, bloom at the top of the stem from August to September. The flower-head is the only bisexual ray flower. The bracts are bell-shaped with 3 or 4 rows of involucre bracts. The fruit is a dark brown, cylindrical, achene with pappus. In Taiwanese Chinese, it is "繖花山柳菊".  宮城県南三陸町歌津「泊崎半島」にて、2022年10月30日撮影。  Shu Suehiro shu@botanic.jp