Choy sum Choy sum Choy sum (also spelled choi sum or "Cai Xin" in modern Pinyin) is a leafy vegetable commonly used in Chinese cuisine. It is a member of the genus "Brassica" of the mustard family, Brassicaceae ("Brassica rapa" var. "parachinensis" or "Brassica chinensis" var. "parachinensis"). Choy sum is a transliteration of the Cantonese name (), which can be literally translated as "heart of the vegetable". It is also known as Chinese Flowering Cabbage. Choy sum is a green leafy vegetable similar to gai lan, and can be characterized by the distinct yellow flowers which it bears. Each flower has four
Fat choy Fat choy Fat choy (; "Nostoc flagelliforme") is a terrestrial cyanobacterium (a type of photosynthetic bacteria) that is used as a vegetable in Chinese cuisine. When dried, the product has the appearance of black hair. For that reason, its name in Chinese means "hair vegetable." When soaked, fat choy has a soft texture which is like very fine vermicelli. Fat choy grows on the ground in the Gobi Desert and the Qinghai Plateau. Over-harvesting on the Mongolian steppes has furthered erosion and desertification in those areas. The Chinese government has limited its harvesting, which has caused its price to increase.