pak-choi \pak-choi\ n. An Asiatic plant (Brassica rapa chinensis) grown for its cluster of edible white stalks with dark green leaves.

Syn: bok choy, bok choi, pak choi, Chinese white cabbage, Brassica rapa chinensis. [WordNet 1.5]

Source: The Collaborative International Dictionary of English v.0.48
 

pe-tsai \pe-tsai\ n. A plant with an elongated celerylike head of broadstalked leaves used as a vegetable in east Asia.

Syn: Chinese cabbage, celery cabbage, napa, Brassica rapa pekinensis. [WordNet 1.5]

Source: The Collaborative International Dictionary of English v.0.48
 

napa \napa\ n. A plant (Brassica rapa pekinensis) with an elongated celerylike head of broadstalked leaves used as a vegetable in east Asia; called also Chinese cabbage.

Syn: Chinese cabbage, celery cabbage, pe-tsai, Brassica rapa pekinensis. [WordNet 1.5]

Source: The Collaborative International Dictionary of English v.0.48
 

Brassica \Bras"si*ca\, prop. n. [L., cabbage.]

(Bot.) A genus of plants embracing several species and varieties differing much in appearance and qualities: such as the common cabbage (Brassica oleracea), broccoli, cauliflowers, etc.; the wild turnip (Brassica campestris); the common turnip (Brassica rapa); the rape or coleseed (Brassica napus), etc. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

Brassica rapa

Source: WordNet (r) 2.0