えぞのこうぼうむぎ (蝦夷の弘法麦) [Index] [Back] わが国の本州北部から北海道の北部・東部、それに千島列島やカムチャッカ半島、サハリン、アラスカ、北アメリカの西海岸に分布しています。海岸の砂地に生え、高さは２０〜３０センチになります。根茎は太くて長く、這って広がります。茎は鋭い３稜形でざらつき、葉は線形です。５月から７月ごろ、茎頂に長さ４〜６センチの卵形から長楕円形の穂状の花序を出し、小穂を多数つけます。頂部に雄花、基部に雌花をつける両性株と、別ベの雌雄異株があります。 カヤツリグサ科スゲ属の多年草で、学名は Carex macrocephala (syn. Carex macrocephala f. bracteata)。英名は Big-head sedge、Largehead sedge。 The Big-head sedge (Carex macrocephala) belongs to Cyperaceae (the Sedge family). It is a perennial herb that is distributed from northern Honshu to northern and eastern Hokkaido in Japan, as well as the Kuril Islands, the Kamchatka Peninsula, Sakhalin, Alaska, and the west coast of North America. It grows in sandy soil along the coast and reaches a height of 20 to 30 cm. The rhizome is thick, long, and creeping. The stem is sharp, with three ribs and rough, and the leaves are linear. From May to July, it produces spike-like inflorescences 4 to 6 cm long, ranging from ovate to oblong, with numerous spikelets. There are hermaphroditic plants with male flowers at the top and female flowers at the base, and separate dioecious plants. 北海道礼文町船泊村鉄府にて、2025年06月10日撮影。 Shu Suehiro shu@botanic.jp