Also sometimes known as bok choy, pak choi, or even Chinese Cabbage.
"Chinese cabbage can refer to two distinct varieties of Chinese leaf vegetables often used in Chinese cuisine: Pekinensis (napa cabbage) and Chinensis (bok choi). These vegetables are both variant cultivars or subspecies of the turnip and belong to the same genus as such Western staples as cabbage, broccoli, and cauliflower. Both have many variations in name, spelling, and scientific classification, especially the bok choy (B. rapa chinensis) variety." Read from Wikipedia...