Ushinohitai - Cow's forehead

…It grows in clusters around waterside areas and ditches, and is an annual plant of the Polygonaceae family whose seeds resemble those of buckwheat (illustration). Its other name, Ushinohitai, is based on the shape of its leaves. The stems creep along the ground, take root at the nodes, and are highly branched. …

*Some of the terminology explanations that mention "Ushinohitai" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…水辺や溝に群生し，種子の形がソバに似ているタデ科一年草（イラスト）。別名のウシノヒタイは葉の形にもとづく。茎は地をはい，節より根を出し，よく分枝する。…

※「ウシノヒタイ」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報