Takana (Leaf mustard) (タカナ)
Takana (scientific name: Brassica juncea var. integlifolia) is a biennial grass belonging to brassica family, and a variety of Brassica juncea. It grows approximately 20 to 60 cm in length. The place of origin is unknown, but it is said that it came to Japan from China in the Heian period. Komatsuna and katsuona are known as its related vegetables. It is grown widely in western Japan. It is also called "Edona."
Depending on the variety and the cultivation method, its leaf and stem are soft and have pungent taste. The pungent component is allyl isosulfocyanate, the same as that of mustard. It is eaten mostly as pickles.
Mt. Aso, Kumamoto Prefecture, in particular, is richly cultivated with takana, and famous for its own way of eating it.
History
Since the description of 'takana' was found in the 'Wamyo-sho' (a dictionary) compiled in the Heian period, it seems to have come to Japan before then.
How to eat
It is eaten as takanazuke (pickled takana) made by pickling takana in salt and fermenting it by lactic acid bacterium. Takana lightly soaked in liquid preparation without fermentation is popular in recent years. The latter one is also called "Shin (New) takanazuke." In the both cases, it is eaten with soy sauce dropped on it if desired, after cut into little pieces. In many cases, finely-shred takanazuke is sold.
"Takana itame" cooked by stir-frying takanazuke in oil is delicious, but if lactic-fermented takanazuke is fried, it generates a distinctive smell, which some people dislike.
Other dishes are well known, such as Takana chahan, fried rice with takanazuke as an ingredient, Takana meshi (rice with takanazuke), the specialty of Aso, and Meharizushi, large sushi wrapped in the uncut pickled leaves of takana. The meharizushi is known for ekiben (a box lunch sold on a train or at a station) specific to Shingu Station.
Karashi takana made by pickling takana with red peppers is popular for the specialty of Kumamoto. Mentai takana made by pickling takana with mentaiko (salted cod roe spiced with red pepper) is known as the specialty of Hakata (Fukuoka City, Fukuoka Prefecture).
Many shops offering tonkotsu ramen (noodle with a thick broth made from boiling pork bones) including Hakata ramen shops prepare takanazuke stir-fried in oil with red pepper to top ramen with. Ramen is seasoned with the combined taste of red pepper, oil and takana.
Convenience stores sell rice balls with takanazuke, and vinegared rice is used for some rice balls.