A type of modified stem, a rhizome is a horizontal organ of a plant that grows just below or along the soil surface. Associated with asparagus, ginger, potatoes, and other ground plants, rhizomes function to store starches, proteins, and nutrients, as well as to spread and form new plants. Bamboo is a prime example of a plant with underground rhizomes. It has the special property of vegetative reproduction, in which the nutrients stored by the rhizome are used to facilitate the growth of new shoots. Such a process enables lateral spread of the bamboo, a helpful reproductive aspect.