Bur clover

It is a biennial herb of the legume family (APG classification: Fabaceae). The stem stands at an angle and is about 60 cm tall. The leaves are compound leaves consisting of three leaflets, with long petioles. The leaflets are obovate and slightly concave at the tip. In spring, several yellow butterfly-shaped flowers appear in the leaf axils. The fruits are spirally rolled globular, 5 to 8 mm in diameter. It is a forage crop, and is commonly called bur clover because it has bur-like thorns along the edges of the fruit. Native to Europe, it is said to have been introduced to Japan during the Edo period, but there is also a theory that it was introduced from Korea even earlier. It is cut green and used as feed, but can also be used for hay and silage. It can also be ploughed into rice fields as green manure. It is sown in autumn. It is weak to cold, and is mainly used as a second crop in rice paddies in western Japan. Some species have become naturalized in warm areas.

[Hoshikawa Kiyochika October 18, 2019]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

マメ科（APG分類：マメ科）の一、二年草。茎は斜めに立ち、高さ約60センチメートル。葉は3枚の小葉からなる複葉で、葉柄は長い。小葉は倒卵形で先がややくぼむ。春、葉腋(ようえき)に黄色の蝶形花(ちょうけいか)を数個つける。果実は螺旋(らせん)状に巻いた球形で、径5～8ミリメートル。飼料作物で、果実の縁(へり)に沿って、いがburのような刺(とげ)があるので一般にバークローバーとよぶ。ヨーロッパ原産で、日本には江戸時代に渡来したとされるが、さらに古く朝鮮から渡来したとする説もある。青刈りして飼料とするが、乾草やサイレージにもする。また、田に鋤(す)き込んで緑肥とする。播種(はしゅ)期は秋。寒さに弱く、おもに西日本で水田裏作にする。暖地では野生化しているものもある。

［星川清親　2019年10月18日］

出典　小学館　日本大百科全書(ニッポニカ)日本大百科全書(ニッポニカ)について　情報 | 凡例