Brassica rapa


Brassica rapa is a plant species growing in various widely cultivated forms including the turnip ; napa cabbage, bomdong, bok choy, and rapini; and Brassica rapa subsp. oleifera, an oilseed which has many common names, including turnip rape, field mustard, bird rape, and keblock.
The oil made from the seed is sometimes also called canola or colza, which is one reason why it is sometimes confused with rapeseed oil, but this comes from a different Brassica species, Brassica napus. The oilseeds known as canola are sometimes particular varieties of Brassica rapa but usually the related species Brassica napus and Brassica juncea.

History

Oilseed subspecies of Brassica rapa may have been domesticated several times from the Mediterranean to India, starting as early as 2000 BC. Edible turnips were possibly first cultivated in northern Europe, and were an important food in ancient Rome. The turnip then spread east to China, and reached Japan by 700 AD.
In the 18th century the turnip and the oilseed-producing variants were seen as being different species by Carl Linnaeus who named them B. rapa and B. campestris. 20th-century taxonomists found that the plants were cross fertile and thus belonged to the same species. Since the turnip had been named first by Linnaeus, the name Brassica rapa was adopted.
Many butterflies, including the small white, feed from and pollinate the B. rapa flowers.

Cultivars