As illustrated, this vegetable is typically sold as entire plants - shoot plus root. The cultivated varieties are generally large, 6-10 inches in length, with oval leaves that may be green or green with dark red centres. In addition, in Hong Kong, a small 4-5 inch version of this vegetable sometimes reaches the outlying markets. Its leaves are oval but much smaller, and the plant may be dominated by granular flower-and-seed stalks. This is a wild species, related to the cultivated one.

Select plants with many and large leaves. The red-leaved variety is considered by some to be more choice, but it tastes and generally costs the same.