A tuber is a part of the plant that grows beneath the soil’s surface. The tuber is used by the plant to store valuable nutrients and water. The reserve of a tuber’s nutrients and energy are used by the plant during periods of drought or during the winter months.
There are two types of tubers: stem tubers and root tubers. Stem tubers form near the soil’s surface. A stem grows out of the tuber’s topside and roots grow out of the bottom of the stem tuber. The stem tuber’s underground stems are considered thickened rhizomes. Around the underground parent stem tuber, smaller baby stem tubers form.