Which of the following plant species reproduces by rhizomes?

American Pondweed is known for reproducing through rhizomes, which are horizontal underground stems that can produce new shoots and roots. This type of reproduction allows the plant to spread and colonize new areas effectively, contributing to its persistence in aquatic environments. Rhizomes enable the plant to survive adverse conditions by storing energy and nutrients, which is critical for aquatic plants that may experience fluctuations in water levels or other environmental stresses.

In contrast, while other species mentioned may have different reproductive strategies that include seeds or vegetative reproduction via other tissues, American Pondweed's ability to spread and proliferate through rhizomes is distinctive and plays a significant role in its ecological success. This reproductive method contributes to the formation of dense stands of the species, which can impact aquatic ecosystems by providing habitat for aquatic organisms and affecting nutrient dynamics in the waterbody.