日本芜菁（水菜），为十字花科芸苔属的草本植物，芸苔的变种。

Mizuna(ミズナ（水菜）, "water greens"), shui cai, kyona, Japanese mustard, potherb mustard, Japanese greens, California peppergrass, or spider mustard is a cultivated variety of Brassica rapa nipposinica. The name is also used for Brassica juncea var. japonica.