Bok choy is a leafy green vegetable in the Chinese cabbage family, originating in China before the 15th century. Though in the cabbage family, it does not form as a head, but rather as smooth, long green blades, reminiscent of celery. The vegetable is in the same gene family as cauliflower, broccoli and cabbage.
Also known as pak choi, this vegetable is most popular in Chinese cuisine. Adaptable in cooking, it can be boiled, steamed, stir-fried and even deep-fried. It is often found in soups and stir-fries, with over 20 varieties available in Hong Kong.
Bok choy was popularized during the Ming Dynasty by Li Shizen, a naturalist who emphasized the medicinal qualities of the plant. Bok choy contains glucosinolates, which have been reported to prevent cancer in small doses. Like many substances, however, it can be toxic to humans when consumed in large quantities.
Bok choy is high in vitamin A and considered a "powerhouse" vegetable, ranked second in nutrient density in a study by the U.S. Center for Disease Control. It also contains approximately 50 milligrams of vitamin C in a 4-ounce serving.
The scientific name for bok choy is Brassica rapa, and it is of the Chinesis subspecies. Plants of this subspecies are winter-hardy, making them most popular in southern China and Southeast Asia. Being resistant to the cold has increased the popularity of the vegetable in North European countries also.