What type of plant has slender, red, freely branched stems with filiform leaves arranged like fans at the end of the stems?

The characteristic of having slender, red, freely branched stems with filiform leaves that are arranged like fans at the end of the stems distinctly describes sago pondweed. This aquatic plant is known for its unique morphology, which includes elongated stems and narrow, ribbon-like leaves that can give a fan-like appearance at the ends.

Sago pondweed often thrives in various aquatic environments and plays a vital role in the ecology of these habitats. Its structure allows it to adapt well to submerged conditions, making it a common sight in lakes and slow-moving waters. Understanding the features of sago pondweed is crucial because it has specific implications for aquatic ecosystems, including providing habitat and food for various aquatic species.

The other choices do not match the description provided. Brittle naiad typically has a more needle-like leaf structure and does not exhibit red stems. Coontail has a different arrangement of intertwined leaves and lacks the fan shape. Wild celery has broader, more rigid leaves and a different overall stem structure. Recognizing these distinguishing features is essential for accurate identification in aquatic pest management.