||This article needs additional citations for verification. (April 2013)|
Brassica rapa chinensis, called "bok choy" in the United States
|Cultivar group||Chinensis, Pekinensis groups|
|Origin||China, before the 15th Century|
|Cultivar group members||many, see text|
Chinese cabbage (Brassica rapa, subspecies pekinensis and chinensis) can refer to two distinct varieties (see below) of Chinese leaf vegetables used often in Chinese cuisine. These vegetables are both related to the Western cabbage, and are of the same species as the common turnip. Both have many variations in name, spelling and scientific classification–especially the "bok choy" or chinensis variety.
The Ming Dynasty herbalist Li Shizhen studied the Chinese cabbage[ambiguous] for its medicinal qualities. Before this time the Chinese cabbage was largely confined to the Yangtze River Delta region. The Chinese cabbage as it is known today is very similar to a variant cultivated in Zhejiang around the 14th century. During the following centuries, it became popular in northern China and the northern harvest soon exceeded the southern one. Northern cabbages were exported along the Grand Canal of China to Zhejiang and as far south as Guangdong.
They were introduced to Korea, where it became the staple vegetable for making kimchi. In the early 20th century, it was taken to Japan by returning soldiers who had fought in China during the Russo-Japanese War. The Chinese cabbage is now commonly found in markets throughout the world.
|Green pak choi|
There are two distinctly different groups of Brassica rapa used as leaf vegetables in China, and a wide range of varieties within these two groups. The binomial name B. campestris is also used.
This group is the more common of the two, especially outside Asia; names such as napa cabbage, dà báicài (Chinese: 大白菜 lit. "large white vegetable"); Baguio petsay or petsay wombok (Tagalog); Chinese white cabbage; "wong a pak" (hokkein); baechu (Korean), wongbok and hakusai (Japanese: 白菜 or ハクサイ) usually refer to members of this group. Pekinensis cabbages have broad green leaves with white petioles, tightly wrapped in a cylindrical formation and usually forming a compact head. As the group name indicates, this is particularly popular in northern China around Beijing (Peking).
Chinensis varieties do not form heads; instead, they have smooth, dark green leaf blades forming a cluster reminiscent of mustard or celery. Chinensis varieties are popular in southern China and Southeast Asia. Being winter-hardy, they are increasingly grown in Northern Europe. This group was originally classified as its own species under the name B. chinensis by Linnaeus.
Chinensis spelling and naming variations 
Other than the ambiguous term "Chinese cabbage," the most widely used name in North America for the chinensis variety is bok choy (from Cantonese, literally "white vegetable"; also spelled Pak choi, Bok choi, and Pak choy). In the UK, Australia, South Africa, and other Commonwealth Nations, the term Pak choi is used. Less commonly, the descriptive English names Chinese chard, Chinese mustard, celery mustard, and Spoon cabbage are also employed.
In Australia, the New South Wales Department of Primary Industries has redefined many of these names to refer to specific cultivars. In addition, they have introduced the word buk choy to refer to a specific kind of cabbage distinct from pak choy.
In China, three terms are commonly used for this vegetable: the majority of Chinese (about 955 million) speak Mandarin, and for them the term is 油菜 yóu cài (literally "oil vegetable"), since most of the cooking oil in China is extracted from the seed of this plant; Shanghainese speakers (about 90 million in eastern China) use the term 青菜 qīng cài (literally "blue-green vegetable"); although the term 白菜 is pronounced "baak choi" in Cantonese, the same characters are pronounced "bái cài" by Mandarin speakers and used as the name for Napa cabbage which they call "Chinese cabbage" when speaking English.
Commercial variants of Chinensis 
- Pak choi (Chinese: 白菜; literally "white vegetable"; Japanese: 青梗菜 or チンゲンサイ, Chingensai); succulent, white stems with dark green leaves.
- Choy sum (Chinese: 菜心; pinyin: càixīn; literally "vegetable heart"; Hokkien chai sim; Japanese: 菜心 or サイシン, Saishin), this brassica refers to a small, delicate version of Bak choi. In appearance it is more similar to rapini or broccoli rabe, than the typical Bak choi. In English, it can also be called "Flowering Chinese Cabbage" due to the yellow flowers that comes with this particular vegetable. The term "choy sum" is sometimes used to describe the stem of any Chinese cabbage, or the soft inner core of a Bak choi with the tougher outer leaves removed.
- Baby pak choi or mei quin choi, also known as Shanghai Bak choi (Chinese: 上海白菜; pinyin: Shànghǎi báicài (Cantonese: Song Hoi bak choi); Japanese: 青梗菜 or チンゲンサイ, chingensai) refers to greener varieties where the varioles are also green. It is simply a less-mature version that could develop into the white-stemmed variety with more time to grow before being harvested. In Shanghai and other eastern China provinces, it is simply called qīngcài (青菜; literally blue/green vegetable) or qīngjiāngcài (青江菜; literally "blue/green river vegetable").
Nutritional value 
|Nutritional value per 100 g (3.5 oz)|
|Energy||54 kJ (13 kcal)|
|- Dietary fiber||1.0 g|
|Vitamin A equiv.||243 μg (30%)|
|Vitamin A||4468 IU|
|Vitamin C||45 mg (54%)|
|Calcium||105 mg (11%)|
|Iron||0.80 mg (6%)|
|Magnesium||19 mg (5%)|
|Sodium||65 mg (4%)|
|Percentages are relative to
US recommendations for adults.
Source: USDA Nutrient Database
Toxic effects 
Pak choi contains glucosinolates. These compounds have been reported to prevent cancer in small doses, but, like any substance, can be toxic to humans in large doses, particularly to people who are already seriously ill. In 2009, an elderly diabetic woman who had been consuming 1 to 1.5 kg of raw Pak choi per day, in an attempt to treat her diabetes, developed hypothyroidism, for reasons relating to her diabetes, resulting in myxedema coma.
See also 
- "Help is on the way for consumers confused by the wide array of Asian vegetables on sale". 2009-10-22. Archived from the original on 2007-08-20. Retrieved 2011-09-08.
- "Asian vegetable names". Archived from the original on 2006-10-30. Retrieved 2011-09-08.
- Hill, Kathryn (2009-10-22). "Know Your Asian Greens". Retrieved 2010-05-04.
- Harlan, Dr. Timothy S. "Ingredients: Pak choi". Retrieved 2010-08-04.
- Rabin, Roni Caryn (2010-05-24). "Regimens: Eat Your Vegetables, but Not Too Many". The New York Times. Retrieved 2010-06-03.
|Wikimedia Commons has media related to: Brassica rapa subsp. chinensis|
|Wikimedia Commons has media related to: Brassica rapa subsp. pekinensis|
|Wikibooks Cookbook has a recipe/module on|
- Nutritional information on bok choy (with photo of chinensis variety)
- Multilingual taxonomical information from the University of Melbourne
- How to choose, store and use pak choi from Veg Box Recipes