Chinese cabbage
Chinese cabbage ( "Brassica rapa" , subspecies "pekinensis" and "chinensis" ) can refer to two cultivar groups of Chinese leaf vegetables often used in Chinese cuisine: the Pekinensis Group ( napa cabbage ) and the Chinensis Group ( bok choy ) . 
<triplet> Chinese cabbage <subj> Brassica rapa <obj> subclass of <subj> leaf vegetable <obj> subclass of <triplet> napa cabbage <subj> Brassica rapa <obj> parent taxon <triplet> bok choy <subj> Brassica rapa <obj> parent taxon