Choy sum (also choi sum) is a leafy vegetable commonly used in Chinese cuisine. It is a member of the Brassicaceae (mustard) family (Brassica rapa var. parachinensis or Brassica chinensis var. parachinensis).
Rapeseed (Brassica napus), also known as rape,oilseed rape, rapa, rappi, rapaseed (and, in the case of one particular group of cultivars, canola), is a bright yellow flowering member of the familyBrassicaceae (mustard or cabbage family), (油菜p) consumed in China as a vegetable ("yu choy"). The name derives from the Latin for turniprāpa or rāpum, and is first recorded in English at the end of the 14th century.