Noun
English Wikipedia has an article on:komatsunaWikipedia
komatsuna (uncountable)
A leaf vegetable, a form of Brassica rapa, used in Japanese cooking
The Japanese call it Komatsuna. Source: Internet
Komatsuna and spinach are the most important vegetables; as of 2000, Tokyo supplied 32.5% of the komatsuna sold at its central produce market. Source: Internet