Polygonaceae

Both Polygonum capitatum and Polygonum persicaria belong to the genus Polygonum in the family Polygonaceae. They are among the most common perennial herbs in the genus Polygonum, and Polygonum persicaria in particular can be found very commonly on the stone walls of houses in urban areas. While the genus Polygonum contains a vast number of species, these two species share morphological similarities...

Buckwheat, Tartary buckwheat, and Japanese buckwheat are all species that can be found in Japan, either cultivated or naturalized. Buckwheat, in particular, is indispensable to Japanese people as a noodle dish, but few people can distinguish between these three species as plants. These three species differ in the way their flowers grow, the shape of their fruits, etc.