Water pepper

...In the narrow sense, it refers to Polygonum spp., and in the broad sense, it refers to plants similar to Polygonum spp. (such as Polygonum spp., Polygonum sakuraensis, and Polygonum spp.) in the Polygonaceae family. Polygonum spp . (water pepper) (illustration), an annual plant in the Polygonaceae family with spicy leaves that gave rise to the proverb "Even the water pepper-eating insects love it," is also called Polygonum spp. or Polygonum hontade, and means true Polygonum spp. with spicy leaves. The stem is upright, 30-80 cm tall, hairless, and branched. ...

*Some of the terminology that mentions "water pepper" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…狭義にはヤナギタデをさし，広義にはタデ科タデ属Polygonum(英名smartweed,knotgrass,knotweed)のヤナギタデに類似した植物(イヌタデ，サクラタデ，オンタデなど)を総称する。　〈蓼食う虫も好き好き〉の語源となった葉の辛いヤナギタデP.hydropiper L.(英名water pepper)（イラスト）はタデ科の一年草で，マタデ，ホンタデとも呼ばれ，葉の辛い真正のタデを意味する。茎は直立し，高さ30～80cm，無毛で分枝する。…

※「water pepper」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