There are kidney-shaped or oval-shaped bead buds in the leaf axils of yam plants. The name "Zilyuzi" is also called yam seed, commonly known as "yam bean", which has a nourishing effect. Its effect is roughly the same as that of yam: invigorating the lungs and qi, invigorating the spleen and insufficiency, invigorating the kidney and essence, replenishing the heart and calming the nerves, strengthening the mind and increasing intelligence, nourishing blood vessels, relieving cough and relieving asthma, lightening the body and prolonging life. Yam beans are pearl-shaped buds formed on yam vines. They grow on the leaves and have different lengths. The skin is yellow, which turns gray when cooked, with thin skin and fine white flesh. Yam beans are sweet in taste and flat in nature. It enters the three meridians of the spleen, lungs and kidneys, which can nourish the lungs and yin, nourish the kidneys and strengthen the essence. "