1、 Leaf shape

The leaves of yam generally vary greatly, ranging in shape from triangle to wide oval, and some are halberd. As a single leaf, the lower part of the stem is often alternate, the middle and upper part are opposite, and there are also three leaf whorls, but few. The length of leaves is between 3-9 cm and the width is 2-7 cm. The top is sharp, and the base is deep heart-shaped and wide heart-shaped. The margin is 3-lobed, the middle lobe is oval or lanceolate, and the lateral lobe is ear shaped.

2、 Rhizome shape

The stem of yam is divided into aboveground stem and underground stem. The aboveground stem is purplish red, usually dextral, and there is no hair on the surface. The underground stem is a tuber, which is long cylindrical in shape and generally grows vertically, with a length of up to 1 meter. There are a large number of adventitious roots on the surface of the tuber, and some lower parts also grow taproots. There are terminal buds at the root neck and adventitious buds in other places.

3、 Flower and fruit shape

Yam is dioecious. Its male inflorescence is spike shaped, with a length of 2-8 cm. It is usually relatively upright. 2-8 grow from leaf axils and are occasionally arranged in a cone shape. Its inflorescence axis is zigzag, and there are purple brown spots on bracts and petals. The stamens are egg shaped, and the outer petals are 6. The female inflorescence is also spike shaped, with 1-3 inserted between leaf axils. Its fruit is a capsule, the shape is oblate or round, less than 2 cm long, with white powder on the surface.

4、 Picture