1、 Is it a root or a stem

Yams are underground stems. It is the transition of stem and root. It is generally formed by the expansion of the apex of the main stem. It has few bud points. There is only one at the root neck. There are many adventitious roots on the surface, and some lower parts grow main roots. Because there are buds on the tuber, it can be used for cutting cultivation, so that new plants can grow

2、 The look of root

Yam has roots at the lower end, which generally grow horizontally and radially. When it grows to 20 cm, it can extend to the lower soil, up to 60-80 cm deep. In addition to the main root, there are many adventitious roots on the surface of its tuber. They can also absorb water and nutrients and play a key role in the growth of the plant

3、 Morphological characteristics

1. Rhizome: the tuber of yam is long cylindrical and usually grows vertically, with a maximum length of 1 meter. If it is cut off, the section will be white. Its aboveground stem is purplish red and has no hair on the surface

2. Leaves: the leaves of yam are single leaves, mostly alternate in the lower part and opposite in the upper part. Occasionally, there are three leaf whorls. In the seedling stage, the leaves are wide ovate or oval, with great variation in the growth process, usually triangular to wide ovate, and some are halberd. The leaves are 3-9 cm long and 2-7 cm wide, with sharp tips and generally 3-lobed

3. Flowers and fruits: its flowers are divided into male flowers and female flowers. The male inflorescence is 2-8 cm long and relatively upright. Generally, 2-8 flowers are inserted between leaf axils, and sometimes they can be arranged into a cone. There are purple brown spots on bracts and petals, and the female inflorescence is generally only 1-3. Its fruit is a capsule, generally oblate, with white powder on the surface and seeds inside