本草纲目对山药介绍的原文

Dioscorea opposita Thunb., commonly known as Chinese yam or Shan Yao, is a perennial vine that belongs to the Dioscoreaceae family. It is native to China and other parts of East Asia and has been cultivated for thousands of years for its medicinal and culinary uses. The plant has a tuberous root system that can grow up to 1 meter in length and weigh up to 5 kilograms. The roots are cylindrical or spindle-shaped, with a rough, brownish-yellow skin and a white, starchy flesh. The leaves are heart-shaped and alternate along the stem, while the flowers are small and greenish-white. Chinese yam is a popular ingredient in traditional Chinese medicine and is believed to tonify the spleen and stomach, nourish the lungs and kidneys, and promote the production of body fluids. It is also used in cooking, where it is often stir-fried, boiled, or steamed and served as a side