Nanjiang, a perennial herb of Zingiberaceae, is similar in appearance to ginger, but it has strong spicy taste, more fiber and less water. Southern ginger is often used in cooking, as a condiment, and can also be used to make pickles.

Jerusalem artichoke is a perennial herb of Helianthus in Compositae. Zingiber officinale is not a zingiberaceae plant. The edible part of its root has some fibers similar to ginger, but its taste is more crisp, and its nutritional value and efficacy are different from that of ginger. Jerusalem artichoke is rich in starch, inulin and other ingredients. It is usually eaten as a vegetable and can also be used to make inulin and alcohol.

To sum up, Nanjiang and Yangjiang are not the same variety.