Pak Choi is a type of Chinese cabbage (Brassica rapa), and is sometimes referred to as Chinese chard, Chinese mustard or celery mustard. The word “Choi” may also appear as “Choy” for Pak Choi. Pak Choi contains a high amount of vitamin A and approximately 50 mg of vitamin C per 4 ounce serving.
Pak Choi is actually in the subspecies of chinensis within Brassica rapa, and it does not form a head; instead, Pak Choi has smooth, dark-green leaf blades forming a cluster reminiscent of mustard or celery. It is related to the other cabbage-types and the turnip; thus, it must be cultivated in cooler temperatures.