Mustard is another cultivar of  Brassica rapa, a species of vegetable that includes a wide range of subspecies including turnips, bok choy, napa cabbage, among many others. Its preparation methods are similar to choy sum and its growing conditions are similar to mustard greens. Similar to other cool season leafy greens, it can be susceptible to pests such as aphids, caterpillars, or snails and slugs. 

Huay Wai

Leaves are unique green/purple in color with serrated edges. A distinct peppery taste.