Brassica juncea (L.) Czern. et Coss. var. crispifolia Bailey is a species of mustard. In northern China, its stems and leaves are used to make the pickle of the same name. Pickled potherb mustard stays dark green in color and can be used for stir-frying meat and stewing tofu. Those that are pickled and then dried are also known as mei cai (梅菜).