What do rhizomes primarily consist of?

Rhizomes are specialized underground structures that primarily consist of stems. These stems are typically horizontal and serve as a means of vegetative reproduction for many plants. Unlike roots, which primarily function in water and nutrient absorption, rhizomes are capable of producing new shoots and roots at various intervals along their length, facilitating the spread of the plant. They store energy and nutrients, allowing the plant to survive adverse conditions and regenerate after disturbances.

The confusion may arise because rhizomes do have root-like functions in that they support the plant structurally. However, they should be classified based on their stem characteristics, as they have nodes and internodes similar to above-ground stems, making them a critical part of many plant species' life cycles. Rhizomes are essential for species such as grasses, bamboo, and certain perennials, where their ability to spread horizontally allows for dense growth and colonization of an area.