Spirodela polyrrhiza

Spirodela is a North American floating plant, 1–3 cm tall, that grows rapidly if given enough nutrients and light. Pale leaves are a sign of micronutrient deficiencies. It tends to shade the light from plants on the bottom.

It helps prevent algae by shading parts of the aquarium and utilizing nutrients in the water. It grows widely in nature and under optimal conditions. A decorative plant for open aquariums.