What is "brassica rapa"

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.

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.

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.

Brassica rapa L. is a plant consisting of various widely cultivated subspecies including the turnip (a root vegetable); the mizuna, napa cabbage, bok choy, and cime di rapa ( leaf vegetables); and (Brassica rapa subsp. oleifera, an oilseed which has many common names, including field mustard, bird rape, keblock, and colza).

The oil made from the seed is sometimes also called canola, 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 (termed Polish Canola) but usually the related species Brassica napus (rapeseed) and Brassica juncea (mustard greens).

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 pollinate the B. rapa flowers.