Seaweed - Seaweed

A submerged evergreen perennial seaweed of the family Hydrocharisaceae (APG classification: Hydrocharisaceae). Its long, delicate stems crawl along the bottom of the water, and from the nodes produce two oblong, rounded-tipped leaves, 1.0-2.5cm long and 0.6-1.5cm wide. It flowers from July to August. It is usually dioecious and has unisexual flowers, with male flowers having a stalk, three sepals, and no petals. Female flowers have no stalk, two bracts, and bear spherical fruits. It grows naturally in shallow sandy seabeds off the coast of Honshu from the Chubu region westward. It is found from the Indian Ocean to the Western Pacific Ocean. Its name means "marine pondweed." It is also known as seaweed, due to the shape of its leaves.

[Sueo Otaki, September 19, 2018]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

トチカガミ科（APG分類：トチカガミ科）の沈水性常緑多年生海草。茎は繊細で長く水底をはい、節から長楕円(ちょうだえん)形で先が円く、長さ1.0～2.5センチメートル、幅0.6～1.5センチメートルの葉を2枚出す。花期は7～8月。普通は雌雄異株、単性花で雄花は柄(え)があり、萼片(がくへん)は3枚、花弁はない。雌花は柄がなく、2枚の包葉があり、球形の果実をつける。本州の中部地方以西沿岸の浅い海底の砂地に自生。インド洋から西太平洋に分布する。名は海産のヒルムシロの意味。別名は葉形からウミコバンという。

［大滝末男　2018年9月19日］

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