山药是秋冬春三季上市的一种蔬菜,其肉质鲜嫩,煮炒食皆宜,也可加工制罐或制干粉。作为蔬菜,山药营养丰富,含淀粉、蛋白质、维生素和糖类较多,同时它也是一种冬令滋补食品。山药是多年生蔓性植物,食用部分是地下肥大的块茎。地上部茎蔓长达3米多,能旋绕攀援。叶片心脏形,在叶腋处生侧枝,或着生1～3个气生块茎,俗称“山药子”(可 Yam is a vegetable that is marketed in autumn, winter and spring season. Its tender meat, boiled and fried are also suitable for processing. As a vegetable, yam is rich in nutrients, including starch, protein, vitamins and carbohydrates, it is also a winter nutritious food. Yam is a perennial creeping plant, edible part of the underground hypertrophy tubers. Stalks up to 3 meters above ground, can climb around the climb. Leaf heart-shaped, axillary axils in the students, or students 1 to 3 air-born tubers, commonly known as “yam” (