Mizuna
Watercress sushi leafy greensMizuna aka Kyo-na, pot herb mustard, mibuna a variety of wild mustard and itona are all furry-leafed greens used in soups, aemono, and nabemono. They lose their taste if overheated. Kuresson water cress is generally used as a garnish and to add a peppery bite to soups and salads. Occasionally it is even used as a topping for nigirizushi.
Strictly speaking a sansai plant, but most commonly cultivated, mitsuba trefoil or Japanese wild chervil is found in Japan and China. It grows in damp places in early spring and is often used as a topping for misoshiru miso soup, or in the steamed savoury-custard dish, chawan-mushi.