Many types of leafy cabbages are used for vegetables, particularly in the Orient. These vegetables belong to several different species and there are many varieties of each, so the classification is confusing to most people. Green mustard cabbage (kai choy) and white mustard cabbage (pak choy) are two types commonly grown in Hawaii. Kai choy, Brassica juncea, includes the types called kai choy in Hawaii, the mustard greens grown in the southeastern United States, and the rai and sarson grown for oil seéd in India and Pakistan. It is also called brown mustard and Indian mustard. The species is variable, with either smooth or hairy, entire or divided leaves, and narrow or wide petioles. It can be distinguished from pak choy by its somewhat lighter green leaves and shorter green petioles. Pak choy, Brassica campestris (Chinensis group) or B. chinensis, in- cludes types called white cabbage, spoon cabbage, choy sam (Singapore), pechay (Philippines), and taisai and Shirona (Japan), as well as others. Pak choy has darker green leaves than kai choy, and white petioles rather than green. Some varieties of both vegetables are grown for their flowers and flowering stems rather than for the leaves. Both kai choy and pak choy grow well under high tempera- tures, although they will form larger plants and are slower to bolt (flower) when temperatures are cooler.