Brassica juncea
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" (termed Polish canola) but usually the related species "Brassica napus" (rapeseed) and "Brassica juncea" (mustard greens and mizuna).