アブラナ科アブラナ属の一年あるいは二年草で、学名は Brassica rapa var. nipposinica (syn. Brassica rapa var. laciniifolia)。英名はありません。
The "Mizu-na" (Brassica rapa var. nipposinica) belongs to Brassicaceae (the Mustard family). It is an annual or biennial herb that is native to Kyoto Prefecture of Honshu in Japan. This herb has been cultivated there from the early Edo period (1603-1868). It is a tussock and its stems are slender. Leaves are divided into frond. Wild turnip-like flowers are seen in April. The Japanese name "Mizu-na" comes from the fact that it is cultivated by drawing water between the ridges. In the Kanto region, it is called "Kyo-na". The traditional varieties include the Kansai-type, which is mainly grown in the Kinki region and Ibaraki Prefenture, and the Kanto-type, which is mainly grown in the Tokai region. The Kansai type has deep leaf incisions and a thin leaf stalk, and is characterized by the fact that it rarely forms a bushy plant when harvested, and is mainly used for salads and Harihari-nabe. On the other hand, the Kanto type has relatively shallow leaf incisions and a thick leaf stalk, and is characterized by the fact that it forms a bushy plant, and is used exclusively for cooking and pickles.