Also known as eggplant lotus and bulbous cabbage, it is a biennial herb in Cruciferae. According to the color of bulb skin, it can be divided into three types: green, green and white, and purple.

According to the length of growth period, it can be divided into three types: early maturity, middle maturity and late maturity. Early-maturing varieties have short plants and small leaves, which are harvested 50-60 days after planting. Representative varieties include Beijing Zaobai and Tianjin Xiaoyingzi. The middle and late maturity varieties have strong growth potential and many large leaves, and it takes 80- 100 days from planting to harvesting.

The pod is long and cylindrical, with a short beak and swelling at the base. The seeds are small, spherical, with a diameter of 1~2 mm and tiny dens.

The kohlrabi is smooth and hairless, and its stem is short, 2~4 cm from the ground, and it begins to swell into a hard, oblong, spherical or oblate fleshy bulb with leaves, with a diameter of 5~ 10 cm. The outer skin is usually light green, and the inside is white.